How much for a running 6 bolt?
 

I'm trying to buy a replacement 6 bolt, and i found one that's been sitting for a couple years, but was in good running condition when it was taken out. It's an engine with a timing belt and nothing else, no manifolds, valve cover, oil filter housing, transmission, etc. Top and bottom end only. What's a fair price for something like this? Niether of us had an idea what it was worth so i'd like a an idea from you guys!
Thanks.