There are multiple stores selling jerseys on those sites, so I guess it all depends on which store you purchase from. I recently purchased an Indians throwback jersey and I have to say that the quality is impeccable. I wore it to a game a few weeks ago and received multiple compliments. As far as size, I purchased a Med (size 40, I believe) and it fits perfectly. Some stores, if you clink around a bit, will have a size chart which is helpful.