Before the internet existed there were different records that were regarded as rare and extremely sought after in different areas - perhaps because a local DJ used to spin them or because someone had managed to identify them from a mixtape.
here are some that I remember were holy grails back in around 1994/95 -
DJ Excel - Just When You Thought It was Safe
The Invisible Man - The End
99 Red Baloons
Trip II The Moon (all parts)
all of the above would command £20+ which was a lot of money back then. This was my experience when speaking with people at record shops in the Sutton/Kingston/Croydon area.
plus Proteus, surely...and on a more obscure tip the Finrg / finnish freeform (admittedly a pretty niche subgenre but that's at least one sound i would say is genuinely Finnish!)
back on topic - I certainly remember even in the earlier days of the internet it was crazy how much a lot of imports could go for - tunes that were literally in bargain bins in Holland, italy or Spain, you could sell for decent money to people in the UK.
so i can only imagine in the 90s...although would the fact it was harder to find out what tunes were called, not balance that out?