The first thing you need to understand is dhgate does NOT sell jerseys. It is a marketplace for many different sellers to sell their stuff. That is why you need to find a good seller at dhgate and get from them. For example I got my most recent ones this season from a seller called "realfine" and they were good. Others here got some from that seller as well, that's why I ordered from them.
It is like everything else, some sellers there have good quality stuff and some have crap. If you go there and buy from some random, cheapest price, seller you see you might well get a powder blue Bills jersey If you find a good seller you should be fine. But you take that risk when buying a knockoff. If you cannot deal with that then you are better off buying from the Bills store.