I am currently selling Dungeon Defenders things.
Mana:
1billion - $3
2billion - $5
Items:
4 Piece Armor Sets - $16
Weapons or Pets - $5 each
Armor Set, Weapon, Pet and 2Billion Mana bundle - $24
Stage Clears:
Any Map Survival Wave 27-30 clear - $10
You get to keep all the items that drop on that level, the stage will be done in Nightmare Hardcore Mixmode Survival to ensure the highest quality loot that can drop.