I'm resurrecting this purposefully, especially since I'm seeing more memes about flexing on the poors these days. I was kinda thinking about this topic further as I was catching up on the podcasts. I want to give a different perspective, which is that I think the concept of grade vs quality is lost on people.
Quality is essentially how well you execute on your requirements. If you're advertising a rifle as good for 10k rounds, and it suffers a failure at 1k rounds, well, you've got a quality problem. This is essentially the problem with a lot of the budget ARs - you might even have what are mostly nominally decent parts, but they're either assembled incorrectly or have systemic issues (over-gassed and beating itself to death in 5k rounds).
Grade, though, is essentially your set of technical requirements. If you're trying to hit that $800 price point and you omit chrome lining, ambi-safety, ambi-bolt-release, a fancy muzzle device, etc. and maybe set the accuracy standard to 1.5MOA, that's purposefully going to be a lower grade gun than a modern KAC SR-15, which I think most people would rightfully designate a high grade gun.
Low quality is NEVER acceptable. Lower grade may be acceptable depending on use case. It is entirely possible to have a low-grade, high-quality gun. It may not be ultra-cheap - quality costs money - but it could very well be a very reasonable deal for certain uses. You could make a good argument, for example, that the Colt LE6920 is a pretty good example of a medium-to-low-grade, high-quality gun. Not a lot of frills and no promised accuracy standard, but executed very well (or it was in the past, anyways).
There are a lot of manufacturers out there marketing their low-ish grade guns as high grade guns. Ironically, they do themselves a disservice, because by failing to fulfill their implied high requirements, they wind up with guns that are perceived as low quality.