I have several $15 jerseys from Aliexpress, and a few $100+ ones from Ornot. The Ornot jerseys fit better, and use a nicer (feeling) fabric. Apart from that, I see no reason for the almost 10x price difference. Some of the newer Ali jerseys use the same advanced fabrics you see in high end brand jerseys, and I've found a few that even fit almost as nice as my brand name stuff. The quick and dismissive "hurr durr Chinese quality suxxxxxxxxxxx" comments are from people who obviously don't wear them. I'm not saying there aren't cheap, crappy, ill-fitting jerseys to be found, nor am I even suggesting the majority are not of poor quality, fit, and construction, but I've bought enough of these to have found some that really are on par with $100+ jerseys.
The bottom line is there really is no reason to pay for an expensive jersey, unless you really want to pay for the name, and (potentially) a slightly better fit. The fabric and construction on some of the cheap cheap jerseys is quite good. Bibs on the other hand, that is a completely different story (from what I've found)...