Searching for possible costumes, for our band

As for our music performance we'll be need costumes, our group has been looking for various costumes from the internet to fancy dress shops. We came across some interesting things but a lot of the costumes were overpriced or just too expensive for our budget. Due to this, our group is going to look on some websites that have used costumes so we don't have to spend a stupid price for one. Our budget per costume would be around 10-50 pounds as we thought that's a reasonable price and anything over would be too much considering we also need more things that just costumes (props, makeup etc.)