I honestly think folks were not thinking about this stuff in the 70s - early 90s. #1s, hot artists, 1st apps, "rarer" platinum edition, sure, maybe a big story arc... "I'll buy the last issue because the print run is low," not so much....maybe they bought it because the book was going out with a bang for the last issue (and some last issues were simply set-ups for a re-boot). I got Conan 275 out of a quarter box as a leftover from the rack that did not sell. Great cover, amazing it did not sell out at my old shop just from nostalgia. IF 15 was worth something because it was Byrne's 1st X-Men work. Maybe Star Wars 107 was selling for a slight premium a few years after it came out? Honestly, I cannot remember. That title was so dead for years, I bought #1s out of $1-$2 boxes. The interweb gives one a better sense of whether something is hard to find. "Rare" last issues, variants, etc. all became more of an issue on the interwebs. When did people start caring en masse about the 30/35 cent variants outside of Star Wars 1?