Thanks for the sound economic advice. I tend to view bikes with undue optimism. There is a site containing advice on buying and flipping bikes, called something like bicyclewebsite.com or bikewebsite.com, in which the author sets forth his rules on bike prices. He advocates setting a target selling price of triple the cost of the bike and required parts. If that price is higher than the typical sale price of bikes of that vintage and model, then he passes. But his prices are for Oregon of 1989, so the site's text is dated. I think it's a book that was transcribed to the Internet site. Your $100 margin sounds safer.