There's a huge difference between 60 000 km and 100 000 mi.
That sounds like a crapload of money for an older engine.
Seriously, aside from a minority of FWD GM enthusiasts, the 3800 SC isn't an engine commonly sought out by performance enthusiasts.
Better to buy from an average person who just wants to get rid of an engine, rather than an enthusiast who knows the 3800 SC is well regarded in the Fiero community.
A used engine is a used engine... I would pay the same for a Cavalier engine. Just because it has more value to you, doesn't mean it has more value on the used engine market.
You can always wait a few weeks before giving that guy an offer. Once he realizes that nobody wants a Buick grandpa-mobile engine, a lower offer ($500 maybe?) should work. To him, anything is better than sending it to the boneyard.
[This message has been edited by pmbrunelle (edited 04-27-2010).]