Main Files

TradeWithWithers

Enables trading with Withers. Can use it without the addons if all you want is easy access to a trader to sell your treasures.

Implemented custom Rich Traders logic to Withers only. Can use both Rich Traders and Trade With Withers at the same time.

Withers will become a trader on save loaded (for people that are already in camp on save loaded). Withers will become a trader when teleporting to camp. On leaving camp Withers will not be a trader (this is for uninstalling mainly).

TradeWithWithersResetInventory

Withers inventory will reset on long rest, so as to prevent his inventory from becoming a mess after selling a bunch of stuff. Made it a seperate file after requests. Use this with base file TradeWithWithers if you want his inventory to reset after long rest. Do not sell modded items to Withers because they won't be removed by the Reset Inventory module unless they are added to its list which requires their UUIDs.

Miscellaneous Files

NukeWithersGold

Only need this if you encounter the duped gold bug where Withers has accumulated an insane amount of gold. Uninstall everything, install this and load your save. It should be fixed once you're loaded in the game. If Withers has any gold left in his inventory then spam open/close his trading menu until he doesn't. Save your game and you're done.

Optional Files

Added optional Addons that add a bunch of items in his inventory. Doesn't include items tagged cinematic or quest.

The items are added to Withers' trading menu when you open it and they are removed when it is closed so that it is not cheesable. This means that if you sell a Healing Potion to withers, it will be removed as well, since it is in the list of the Potions items. This applies to all of the items in his addons' lists. Shouldn't matter that much but just letting you know.

TradeWithWithersAddonArmor

Adds every armor piece (gear).

TradeWithWithersAddonArmorRandom

Will randomly select and add four armor pieces. Items change after long rest.

TradeWithWithersAddonCampClothes

Adds every camp clothing piece.

TradeWithWithersAddonCampClothesRandom

Will randomly select and add four camp clothing pieces. Items change after long rest.

TradeWithWithersAddonGrenades

Adds every item tagged grenade. Seems like they are just throwable items/explosives.

TradeWithWithersAddonGrenadesRandom

Will randomly select and add four grenade items. Items change after long rest.

TradeWithWithersAddonPotions

Adds every potion/elixir.

TradeWithWithersAddonPotionsRandom

Will randomly select and add four potions. Items change after long rest.

TradeWithWithersAddonScrolls

Adds every scroll.

TradeWithWithersAddonScrollsRandom

Will randomly select and add four scrolls. Items change after long rest.

TradeWithWithersAddonWeapons

Adds every weapon.

TradeWithWithersAddonWeaponsRandom

Will randomly select and add four weapons. Items change after long rest.

TradeWithWithersAddonArrows

Adds every arrow item.

TradeWithWithersAddonArrowsRandom

Will randomly select and add four arrows. Items change after long rest.

TradeWithWithersAddonAIO

All of the addon files in one file. Use this one if you want to use every addon file. DO NOT USE ANY OTHER ADDON FILE WITH THIS. BUT YOU NEED TO USE THE BASE FILE STILL.

TradeWithWithersAddonAIORandom

Will randomly select and add four items out of every type (weapons, armor, arrows, potions, etc). Items change after long rest.

More addons

Trade with Withers Add-on - Essential Supplies

Trade with Withers Add-on - Bling Edition

Trade with Withers - Magical Items only and more random selections

Trade with Withers Addon - Containers

The random variants allow you to essentially build your custom Treasure Table. For example, I will use Random potions, random camping clothes and random grenades.

Installation

Backup your save files before using. No issues as of now but it's always best to backup your save with each new mod you're using.
Download BG3ModManager.
Download and install Baldur's Gate 3 Script Extender.
Download TradeWithWithers. You should get a .zip file. You can use TradeWithWithersResetInventory with it as well.
Drag and drop the .zip file in BG3ModManager.
Move the mod up and down in your Load Order. I had to do that in order for it to appear in modsettings.lsx.
If you want to install the addon files you follow the same procedure. They are optional. They are inside a zip archive named "OPTIONAL". You need to unzip this archive first.
Load Order shouldn't matter.
Click the save icon in the Mod Manager ("Save Load Order to file").
Make sure that the mod was included in your modsettings.lsx file. You should have these lines in it if you did everything correctly:

<node id="ModuleShortDesc">
<attribute id="Folder" value="TradeWithWithers" type="LSString" />
<attribute id="MD5" value="" type="LSString" />
<attribute id="Name" value="TradeWithWithers" type="LSString" />
<attribute id="UUID" value="c7c3ba79-97bd-411e-82f4-1c615e9945a7" type="FixedString" />
<attribute id="Version64" value="36028797018963969" type="int64" />
</node>

Notes

Don't sell modded items to Withers. Modded items should have specific UUIDs that I need to add in the ResetInventory's list.

If I've left a quest item in the addon files let me know. Don't want to corrupt saves/break flags.

Should have some duplicate items. Shouldn't matter. Some of them stack correctly when you buy them, like potions. Might clean them up later.

There are a bunch of items that I haven't seen before. A club weapon with a chair model. Some weird underwear and clothes. Might be unreleased/test\npc files? Still pretty early into the game so I have no idea.

If you use every addon file be aware that it will take a while (1-2 secs) for the trading menu to load and close. If the items are not sorted correctly (rarity) exit the trading menu and re-enter or change to Trade from the Barter menu.

The items are added to Withers' trading menu when you open it and they are removed when it is closed so that it is not cheesable. This means that if you sell a Healing Potion to withers, it will be removed as well, since it is in the list of the Potions items. This applies to all of the items in his lists. Shouldn't matter that much but just letting you know.

FAQs

Why is everything so expensive?

I made the addons before the updates. The trading menu used to show stacks correctly as you can see from the screenshots. All the items come in stacks of 100. So the price is for 100 of an item. You can select the number you want to buy by double clicking it. After the updates the stacks are not showing up correctly in the trading menu. This seems to affect armor and weapons only. If there's a mod that fixes the stacks you can share it in a comment. Also see FAQ Trade button doesn't appear.

I bought an item and it is heavy?

You bought a bunch of an item that isn't supposed to be stacked. No idea why the devs changed this. This is probably happening with armor/weapons only. Just make sure to double click these items and select only one before buying. If you have bought 100 of a weapon you can either load a save before that or you can split them one by one in your inventory (right click->split).

Sold bags are buggy

Do not sell bags/containers to Withers, especially modded ones. I'm not sure what the devs changed with the updates but it has been reported that they act weird now which wasn't the case when this mod was first made.

Sold bags not resetting after long rest

Do not sell bags/containers to Withers, especially modded ones. I'm not sure what the devs changed with the updates but it has been reported that they act weird now which wasn't the case when this mod was first made.

Modded item not resetting after long rest

Don't sell modded items to Withers. Modded items should have specific UUIDs that I need to add in the ResetInventory's list.

No dialogue option to trade with Withers

Look for the trading button in the bottom left corner. See screenshots for reference.

I uninstalled the mod but Withers is still a trader

Re-install the mod. Enter camp, leave camp, save, close your game, uninstall the mod.

Improve sorting?

Sorting used to be way better before the updates. I have no idea what the devs changed for it to be this bad. If there's a mod that fixes this you can share it in a comment.

What to do if Withers has low attitude towards my character?

You can give him gifts just like in the vanilla game (gift him items in the trading menu) or you can use cheats. Press the "Enter" button in Script Extender's console, you should get this message in the console: "Entering server Lua console."
Paste this in the console and press "Enter":Osi.AddAttitudeTowardsPlayer("S_GLO_JergalAvatar_0133f2ad-e121-4590-b5f0-a79413919805", Osi.GetHostCharacter(), 50)Withers attitude will increase. You can change the number "50" with whatever you need. You can also use negative numbers if you want to decrease his attitude.

Trade button doesn't appear

Don't know if this is still relevant but it seems like it used to be related to ImprovedUI (credits to Gooooooooogs). Don't think it is relevant anymore. I don't use ImprovedUI.

Troubleshooting

If the mod isn't working after the updates, uninstall and reinstall the mod and the dependencies. Make sure to install Baldur's Gate Script Extender with console, so that you can check if the mod is even loading. Make sure the mod appears in your modsettings file. If it doesn't appear in your modsettings file, move the mod a bit in your load order and save the load order until it does.

After the game launches, check Script Extender's console. You should be getting "Configuration for Mod Name" "#number of your mods mod configuration(s) loaded." Something like this:

Configuration for 'Oath_Spells':
MinVersion 1; Feature flags: Lua
Configuration for 'Respec_Spell':
MinVersion 1; Feature flags: Lua
Configuration for 'RichTraders':
MinVersion 1; Feature flags: Lua
3 mod configuration(s) loaded.

If you don't see the mod's name in there, something is wrong on your end. Repeat the same steps. If you see any errors you can share them in your comment/bug report.

Link for Baldur's Gate 3 official Discord server where you can get help: Larian Studios Discord Server

Credits

Credits to Liareth for their files at Developer Resource - Object List - Items Characters Traders since they helped immensely.