Brand new, with bell housing you're looking at about $3k. If I was buying second hand, I'd offer at least $2200. If, it's a friend like you say and he needs the money, I'd at least give him $2500 that way you're saving a little bit and he's not losing too much on the sale. But, if it's a guy that's in need of money, I'd start low and offer him $1900 or $2000.
They are $3K new with the latest and greatest internals from Tremec. That is the T56 Magnum with wider gear faces, larger bearings to handle more load, everything inside is made of a better steel, 31 spline output shaft, the case is 2-3lbs heavier casting (less deflection), triple synchros (better shifting), electronic and mechanic speedo outputs, and a provision for transmission cooler bungs if you were to seriously endurance race with it.
I have one in my Chevelle and FD RX-7. Worth the $$$.