I made the mistake of buying the $30 (shipped) sights off eBay from China. They were, quite literally, garbage. The adjustable portion of the rear sight was loose and could move a few MM each direction. Then, as I inspected it to see if it could be tightened, a tiny pin fell out completely and the whole sight fell apart.
There was no way they could ever hold 50 let alone hold zero and they clearly would never survive the recoil of a chirping cricket let alone a .223.
I do agree, $250+ for a set of irons is crazy... Simply because they're offset 90 degrees. But no irons would be better than that cheap eBay junk. I got my money refunded... Threw the sights in the garbage.