Times change. We didn't know what we had back then. Inflation and such makes these good AKs worth that, especially when cheaper weapons broke into the market. The difference is obvious upon first sight, let alone working the action or firing them. The Chinese could back in the 1980's (and probably still can) crank out these high quality AKs much cheaper than modern Western companies.
Chinese make a lot of junk, but when it comes to small arms, this is not the case. Their AK and SKS series weapons are top notch, and the best of the best.