$219 seems a little bit low for a name brand aluminum frame. (You said it was unsold at this price.) Below $395 seems about right for a name brand aluminum frame. Maybe $300? One of the appeals of aluminum frames is the cheap price. New, and used. I would guess the Merckx aluminum frames were $800-1200 brand new. So 75% depreciation after 5-10 years makes sense economically. Sadly, bicycle components do not seem to hold value very well over time.
I do not have any experience selling bikes. So cannot comment on Tommy's plans to build up his used, old, Merckx aluminum frame with old, used, Campagnolo parts. But I'd guess if he can manage to get his costs for all the parts out of the sale price, he should jump for joy.