I have one of the EM versions in very nice condition. I've noticed that the SS version of this game does not get much love, but everyone that plays my EM seems to really like it. For a multi-player, there is a lot to do on the PF and I think it plays every bit as fun as it's sibling, Grand Prix.
I would agree with the upper end of Locksmiths valuation if the machine is in very good condition. Around here, sellers often ask $800-1000 for a dirty, less-interesting game that needs work.