gs-r tranny. How much is it worth?

How much is a 92-93 gs-r tranny worth. I almost bought one for $600 with 45k on it a few months ago. But now somone is sellin one for $375obo with 60k on it. But its been sitting in his garage for a long time like years. Could anything go wrong with it from sitting? Should I scoop it up?

450 is the going rate around so cal. 600 are the hydro trannys