With the exception of the one I found very cheaply, mentioned above, I've seen a lot of them selling in the $250-$325 range... not just the Firestar Plus, but the Firestars, the Megastars, and the Ultrastars. You could do worse for the money, if you find one in that price range.
Extra mags would add a little to the price -- as they're rare for some of the models.