This game is simple - Post a funny made-up item for sale, and the next person “buys” it for a funny amount of a funny currency… e.g.

1: Selling a mouldy slice of bread.
2: Ill buy for 200 rice crispies. Selling a piano with no keys.
3: Ill buy for 10 USB leads. Selling a hair.

I shall begin with:

Selling a box of Used-Up P0rno