There is definitely some good stuff on there, but just like trademe there is also some utter rubbish. Depending on what it is I sometimes message the seller about a few things and try and get a feel for them.
Anyway, got one of these off the link you put up. Not too bad but takes a bit of tinkering to get it sitting right, and the shoulders are really pointy. I’m not the big and the form of them is still a bit small feeling. Still, for the price I’m happy with it.