I don't think people are being too fair about quality. I used to buy only dollar stone sunglasses because I saw them as disposable. I saw them as disposable because they always broke. If I branched out into "luxury" mall brand territory, they would also just break but I was out $80 instead of $5. I'm talking lifespans of one month. I don't treat my stuff like crap. I really try and take care of my things. But whether I was buying overpriced Armani Exchange (yeah, I know... I go there for basics because I like their t-shirt fit) or picking them up at some street vendor from whatever no-name asian company that supplies those people, sunglasses would just wear out from normal use.
I finally decided to dive in and get real grownup sunglasses. I researched it a bit but went with Rayban because the styles I always wore were Aviator and Wayfarer knockoffs, and I figured I might as well just go to the source and buy the originals. I purchased both in the span of maybe 6 months back in 2014. They are both still going strong. I baby them less than I ever did my cheap sunglasses. They show no real signs of wear or damage barring the need to get them straightened sometimes and also the lens of the aviator occasionally needing to be popped back in. They are both made in Italy and brand new as of 2014. They are the styles I like and they are the classic proprietors of those styles. The quality as far as I am concerned is excellent, coming from the world of crappy (yet not necessarily cheap) sunglasses. Would I maybe branch out a bit more when shopping for eyeglasses if I didn't wear contacts? Yeah, perhaps. But when it comes to sunglasses, I have exactly what I want with my Aviators and Wayfarers and I finally understand why they are $150 a piece even though when I was younger I used to scoff at prices like that for eyewear. I could have just bought them originally and probably saved a ton of money over the years that went into crappy disposable knockoffs.