Used, working RMs tend to sell for $75. Parts and semi/working for $30-50 or so.
Looks in OK shape. It appears to be the 2nd gen version with the single-trigger, and multiple mode board. Though the noid looks like the 1st gen version, so it might be a mish-mash of parts.
If you can get it for cheap, it might be worth fixing, but parts have dried up, and nobody really works on them anymore.