OK, we all know that for $600 retail you can get a decent SS/FG road bike - Pista, Rush Hour, 925, etc, etc. I went mountain biking for the first time today, and I'd like to get a SS mountain bike, hard tail, front suspension (the bike I borrowed had some gear/chain problems, and I ended up riding it in one speed the whole time anyway). Nothing amazing, but not something that weighs the same as the $250 Trek I borrowed.

A quick search of the web reveals the two Bianchi offerings (Rita and Lewis), which look really nice, but $1400 is a little hard to stomach for something that I probably won't do more than once a month or so. Heck, that'd be about the top of my budget for a new road bike, which I ride a few times a week (when I'm not on the FG). Some of the small manufacturers seems to have nice stuff, but I assume it's out of my price range.

So, is there any decent SS MTB out there for $600 or so? Something with a good frame that would at least allow me to upgrade to new wheels and disc brakes at a later date (I assume that getting discs for $600 is a pipe dream)?