The mod brings two hard to obtain swords. The Instakill Sword and the God Sword. The God Sword is an upgraded version of the Instakill Sword.
When I say hard to obtain I mean you will be at it for probably hours upon hours. The crafting of the swords requires a lot of ingredients from potentially difficult locations.
I feel that the price can be worth the effort at least on a multiplayer server, because you can practically one hit kill anything.
(I'm not sure if these swords can kill every modded entity, but they should do good on most things.)