There is one by me, but it hardly stocks anything. I think turnover is slow in these businesses. Also it was £11 for a second hand bit but £15 if I went and bought a new one... I think it would have to get bigger before I went back for another look!
I tend to prefer to go in to look over things and then order online (so I don't have to carry everything home!). If its second hand then I'd definately want to have a good look at it before spending any money.
There's an amazing one in my area. It does both new and second hand, so if they don't have whatever it is second hand you can pay a bit more and still get it new. They take old stuff in exchange for whatever you need up to that value and have saddles and everything.