Even paying extra for the good "good" part is no guarantee of honesty and quality. Unless you're a juggernaut like Apple, after a while they'll start shoving in sub-par components in the shipments to test your QA and see if they can squeeze more money out of you. It's just how they do business.
There are plenty! The trouble is finding them. Once you do, hold on to them – they can be very valuable.
A good place to start is making sure you're paying a fair price for whatever it is you're buying. Anything too cheap is definitely trouble. (And, of course, this condition is necessary, not sufficient.)
