Fair price for a complete 360 minus carb??

Even as a core, I don't think he's too far off on price. It could be parted out and bring more money than what he's asking for it. If I were in the market for a drop in engine I would probably take the gamble on it knowing that if something went wrong or it didn't work that I could probably part it out and get my money back. If it works, then sounds like it was a good deal.