Transactions (2.0):

Transactions lets you buy and sell items with offers. If you want to sell an item, all you have to do is have the item/items in your inventory add an offer. Once the offer is added, players can search/browse available offers to find what they want. If they do, they can buy it from you and you get money! As of now, Vault is supported!

Features:

Put items up for sale
Search for offers by item name, ID or player name
Buy items with whatever economy plugin you have that works with Vault
Retract an offer if you want to
SQlite support
Permissions

Requirements:

Vault

Known Problems:

Fake item duping (Fake client-side items) caused by (as far as I can tell) Bukkit issues. I'm working on it.

Commands:

/ts - Shows transactions help
/ts list - List the available offers (ID only)
/ts dlist - List the available offers (All info)
/ts offer <itemID> <amount> <price> - Offer a certain number of items for x each
/ts offer <itemName> <amount> <price> Offer a certain number of items for x each
/ts offer <hand> <amount> <price> Offer item in your hand with a certain quantity and for x each
/ts info <offerID> - Shows info about the offer with the given ID
/ts buy <offerID> <amount> - Buy a certain number of items of the given offer ID
/ts search player <player> block <block> - Search for offers matching the given item ID and given player name
/ts search player <player> - Search for offers of a player
/ts search block <block> - Search for offers based item name or ID.
/ts retract <offerID> - Retracts the given offer (If you are the one that posted it)

Permissions:

transactions.list - Allows to perform /ts list
transactions.dlist - Allows to perform /ts dlist
transactions.buy - Allows to perform /ts buy
transactions.retract - Allows to perform /ts retract
transactions.info - Allows to perform /ts info
transactions.offer - Allows to perform /ts offer
transactions.search - Allows to perform /ts search

Video:

This is a little outdated video. Most bugs are solved in version 2.0