When asked, I usually respond that any pair of glasses that's over a decade old, it generally going to be hard to find, but in the day they were as common as Gascans are now.
I think this is a key concept for today's market. I had started a thread years back asking what the definition of rare years was (too lazy to search for it now), and looking back the definition certainly has morphed over the years and further modified as newer collectors join the scene. I LMAO when someone states stuff like the wide release Romoeo and Mars are rare, but that's only because the weren't around when there was an overabundance of product at the retail/eBay/o.com level back in the day.
As you suggested, "rarity" is becoming less and less relevant in my eyes. "Desirability" is more important. I would rather have something blatently cool with backstory but widely release than something ho-hum and only a handful made.
But enough of my soapbox...back to rare shit.