As a mostly buyer I have bought many clothing items on here. Even if a seller doesn't write it on there listing I know unless I am buying a style and brand I know I am taking a chance.
There have been a few times that I have got it wrong so I just resold the item. Yes I lost a little but it's my own fault.
I think that if u let people have refunds they need to pay postage costs to return and u should take postage off the item that it cost u to send it.