Just kidding I don't have shit for sale.

YOU CAN MAKE YOUR OWN FUN MERCH!!!!

Here are some ideas:
A t-shirt that says "RETARD" on the front
A t-shirt that says "FUN" on the front
A t-shirt that says "0 The Fool" on the front
Stickers that say "FUN!!"
Stickers of a fun hero's face