This is simply case of someone (iApex's uncle) erroneously thinking the engine is worth more than it really is. Waaaaaaay more than it really is! (unfortunately) We've all come across people that have seen a Hemi cuda sell for 1 million on Barrett -Jackson so they think the four door, 6 cylinder, 1976 Dodge Dart they just dragged out of the woods MUST be worth at least 20k. This is kind of like that.
iApex: The 700.00 Stealthmode offered is a VERY fair price for that stuff. It's really nice of you to try to help your uncle out. Perhaps you can help educate him and he can put a few dollars in his pocket. If he wants to hold out for 2500.00 or more, there is really nothing you can do about it. At least you can say you tried, right?