I dunno
It's true that premium scopes from years ago are not the equal of similar models of today, optic quality wise. I see the difference in brightness at twilight. That matters on a hunting rifle, not near as critical on an informal plinker or range rifle.
But I wouldn't go so far as to label a Vari-X as "poor quality". It is still a Leupold, rugged and reliable, and very likely bright enough for much of the hunting and shooting most of us do. If indeed the Vari-X phased out 20-30 years or ago, that is still the late 80's, earlyt 1990's (gosh) and things were not all that primitive then. Heck, my best pickup was make in 1991!!!!
Leupold still does honor their warranty to any owner. Were I to purchase that scope (I'd offer no more than $150, cash, bet he'd take it), and intend to hunt it, I'd ship that rascal off to Oregon and ask Leupold to clean and service it, overhaul as needed. I might ask them to install the reticle of my choice (about $55 last time I did it). I would think that it would go 15+ years or so, with tight seals and useable clarity under normal use, likely more.
I dno't have any Vari-X's, but hunt a number of Vari-X II's, Vari-X III's with no complaints at all.