Computer collecting of systems from the 70's and early 80's are pretty common. Atari, Commodore, Amiga, etc. True gaming computers, of which the Amiga was the last, and largely died out by the start of the 90's. Many of these systems used cartridge games, the same as the consoles. Those are fair game. However, I would agree that the condition of the old equipment and media, particularly the floppy disks and drives, would likely be a wreck by now. However, many of the old computer games had similar if not better box artwork, manuals, inserts, etc. Personally, I still have a ton of old PC games (CD) and some 3 1/2" disks. But I cannot be bothered installing them and getting them to work. It was always such a hassle. Therefore, I would stick with games that run without installation, like the old Amiga or Tandy did. In terms of rarity, I would figure complete games from the 80's would be pretty hard to find these days. But how do you collect for a Commodore 64, where many of the thousands of games were available via modem download or mail order, and most were clones of something else and stunk?