I know that the Commodore Vic 20 tape of Ultima Escape from Mt. Drash is ridiculously rare and that boxed copies of it are practically impossible to own, but a starting bid of 2500$ for a tape and a manual without a box do seem quite steep. I mean the tape isn't in such a hot condition anyway... Still, incredibly rich Sierra and Origin collectors should look no further than this very Ultima Escape from Mt. Drash link. It's on eBay, it is.
Oh, and for those wondering, no, Richard Garriott did not create this Ultima title. Actually, he wasn't even aware of its existence for quite a few years since the game was published. Interesting, eh? Well, you can find more about this most obscure of games here, here, here and here.