All of my old York milled plates are either spot on, or off by < .5 lbs. They would mill the backs to shave them to weight.
All of my Ivanko 45's (eight of them) are on the money.
I had an Eleiko set for a long time but I sold it off, it just took up room. But yes, the junk plates at Dicks Sports (and lots of others) are off by 2, 3 even saw some off by 4 lbs.
(Chinese Weider plates, etc).