I woulld guess anywhere from 1700-1900 but no more than that range because a new 15in 867 is 1999 after thhe recent price cuts and there is a smaller market at the moment because people are waiting for upgrades. The gig of ram might push that towards 1900 but defiantley not more than the new machine imo.
with similar specs is only at 1250 with a day left....I suggest you watch ebay to get a good idea of what they go for because for most sellers if they can't finding a buyer on one of the forums sites they move to ebay.