I'd say ~$300 in the condition you describe, but I'm sure others here might say more. Those always seem to go for more than I expect, but the game really never did much for me.
I bought mine a few months back. It works great and is in ok cosmetic condition, but I will restore it (new CPO, new t-molding, paint, and restencil). I paid $300.
I'm sure some would pay more but I remember when the market was better a few years back a member here in the CA area put one on ebay and it sold for $400. I believe it was in similar condition to what you mention. The market is down though so I would say $300 is reasonable.