Plates designed for competitions are accurate...If you are just a gym rat...Why pay for that accuracy?
The problem is with the really cheap plates you can see accurary swings of +/- 5-10%. It might not seem like a lot, but you'll notice it on certain lifts. Some people say, "Well, just weigh them out and mark it on the side", but hunting around to make sure your plates are close gets old day after day. It's better just to buy once, and buy nice.
That being said, most good quality gym plates are garanteed to be +/- 2% (York, Ivanko, etc.....) of stated weight, that's plenty reasonable for home gym stuff.
Good gym plates were running about $ .75-1.00/lb used pre-Covid, one hopes we'll see prices like that again once things calm down.
