I casually watch the vintage MTB market. For years, I saw cool, rare machines selling for peanuts, or not selling. In the past year I've noticed that selling prices seem to be rising to levels that make more sense.

Examples:
Bridgestone MB-Zip - I see them sell for $1000 a few times a year on eBay, if they are in nice shape. A bare frame just fetched $600. Ratty ones get $600-700.
Bridgestone MB-1 - these still only go for $400-500.
Ritchey P-23 - these always go for $1200-1500, at least that I've seen.
Bridgestone XO-1 - I know, not a MTB but surely hybrids have been even less respected than MTBs? These routinely get $1000 at minimum.

Those, I admit, are the only models I watch. (I own a Zip and a XO-1, and always wanted a P-23.)

Are you watching any vintage MTBs? What are you seeing as far as values? Any particular model(s) you consider most interesting?