The latest remarkable auction is none other than the legendary computer role playing game hybrid, Shadowkeep, from 1984, by Trillium, for the Apple II, which sold for $529.00 (with free shipping). Trillium was best known for their high quality text and graphics adventures, like Amazon and Dragonworld, that featured solid parsers and excellent graphics, and were typically written in partnership with a famous author. Shadowkeep was something of a departure for the company as it was essentially a lushly illustrated role playing game that had a text-based interface. As for this game's famous author connection, Alan Dean Foster created a companion book for the game with the same title whose existence was advertised prominently on the game box (actually, the company's usual thick multi-fold folder) cover.
Much like with Penguin Software having to change their name to Polarium after Penguin the book publisher took notice, Trillium ended up having to change their name to Telarium after Trillium Press got on their case. That's why today, Trillium versions of the games are worth more than the later Telarium versions, though most releases were otherwise identical. I believe I personally have the complete Telarium Apple II version of Shadowkeep along with the paperback novel, though I'll have to verify if in fact instead it's the Trillium version. In any case, the typical pricing for Shadowkeep has been in the ~$250 range, so for this latest game auction to go for double that is indeed impressive, and is probably due in part to the completeness of the example.
Shadowkeep is also notorious for a few other reasons. First, is an incredibly robust copy protection scheme. Second, is that all of the known Apple II images/ROMs on the Web have been altered. You see, if you play directly on the game disks rather that making play disks, the game is irrecoverably altered. That's right, once you play on the originals, there's no going back to its original state, ever. I have yet to check if my disks are in fact intact or have been played on, and thus, altered. Finally, there's the question of other versions outside of the Apple II version. The Commodore 64 and IBM PC versions were at least ANNOUNCED, and there have been occasional sightings that would make Bigfoot hunters proud, but there's still no credible evidence that those versions of the game were ever actually released.