its a bose 50-me and it sells for 300 new but on ebay i could get one for only like 100 dollars supposevly the ones that cheap are only "scratched and dented" but can the sound quality be messed up? or can the wah wah be rusty or slow? or can it like short out and stuff? could the names of the effects be scratched so you cant see it? because i dont know if i should buy it off ebay now or wait to buy it new.
I've gotten great stuff on ebay. Just look for a seller who has lots of positive rep, and make sure there are pictures to check out.

Avoid things with the description "AS IS" it usually means broken, and you're ****ed after you purchase it... returnwise anyway
it could but that doesn't mean it will.

Just check their feedback and see what people say about the salesperson.