Was there some kind of unusual feature about it that made it sell for that much? There are 3 just like it in the rack at a pawn shop near me for like $350 a piece. Two fools must have gotten into a bidding war.
The MAK-90's are popular now since with the right parts and with a hydraulic press and drill press you can turn one into a pre-ban Chinese Type 56 AK-47 clone. Doubtful that any of them were sold in the early 80's, since they were only imported from 1990 - 1994 to circumvent the "sporting clause" of the George HW Bush 1989 import ban. Bill Clinton finished off any further imports of Chinese pistols, rifles, and ammo in 1994 after Polytech and Norinco reps in the US got caught up in fed sting operations trying to sell RPG rocket launchers and full-auto North Korean AK's to LA street gangs. Both of those companies were fronts for the PLA and were likely all staffed by members of the Chinese equivalent of the KGB.
Maybe they were "unregistered foreign agents" trying to "meddle in our elections"? Or maybe Bubba Bill was just dropping off military tech trade secrets right at their front door? Who knows?
Anyway, after Clinton put the kibosh on any further importation of Chinese guns, they have been steadily increasing in value - particularly the pre-ban AK's and post-ban neutered MAK-90's with the thumb hole stocks. One of the reason AK collectors seem to like them is because they were manufactured in a legitimate foreign state-run arsenal that was used to produce military weaponry.
At any rate, adjusted for inflation, $180 in 1990 would be about $350 in today's money. I paid $600 for mine out the door at a local pawn shop about 2 years ago, then acquired the parts needed for the conversion. Probably got about a grand in it by now, but even that much is a lot less than you would pay for a Type 56 Sporter pre-ban rifle.