The Avtomata Kalashnikov is a military design, produced to military standards.
The ones built for Eastern bloc militaries and inspected for compliance to milspec, yes. The ones built for the U.S. civilian market, sometimes (except for the semiauto-only part, of course), but not always.
There are no "upper tier" or "crap grade" models¹ - they all do as they're designed. If you believe there are "upper tier" AKs, then I guess the propaganda marketing is working.
Well, I own an inexpensive Romanian AK (SAR-1), and I'll have to disagree with some aspects of that one. I do agree that from the standpoint of
reliability, a SAR or WASR will run every bit as well as a Krebs, Arsenal, or converted Saiga. However, some of the latter use higher-grade barrels (little bit better accuracy) and pay more attention to parts fit, finish, etc., so what you get in that department does vary by price. My SAR's finish, both wood and metal, is "industrial" at best, while some of the higher end AK's I've seen are more AR-like in fit and finish.
Some of the higher end AK's also reflect recent Eastern bloc upgrades to the original design, such as the Russian AK103-style 90-degree gas blocks, sidefolding full stocks, and whatnot, and some come with AR-style rear sights.
I also agree with you with regard to magazines. I shoot my AK a lot, and as a result I'd rather have five or ten milsurp ex-Warsaw Pact magazines than one or two ultra-expensive high-end magazines. The cheap milsurp mags work just as well, and I don't care so much about them getting scratched when dropped or when using them to whack the mag release as I would if they were $75 each instead of $10.