Why is everyone suggestion op items like stones or dogis? For fks sake, just think about it they gotta earn money somehow.
My suggestion would be, remove both Goku's dogi and Sun glasses and instead add items that give temporal con, foc, movement speed and others. These can help in farming, doing dungeons and be a very big help for newbies. Also would be nice to be able to convert tokens to zeni (like 10 tokens =10k zeni or more).
Dogis are more cosmetic than OP as they're basically for looks unless you get your hands on a Dogi Ball, which is getting booted from Cash Shop. One or two more dogis isn't going to break anything, especially when they're bound.