Its really all about condition. Most buyers want bikes that are ready to ride: spotless, recently serviced, etc. Project bikes go to buyers looking for something to fix up, at a steep discount to cover the time and $$ in parts, and the risk of hidden problems. Not every "deal" ends up being such a great deal.

I have seen similar Treks go from anywhere from about $50 for a serious project (needed a lot of work) to about $300 for a pristine, beauty, ready to ride.

I bought a late 1980s Trek racing bike project last week for $55. It needed a lot of TLC. But the frame and paint were in very good shape. If a bike has serious issues, to me, it then is only worth what parts on it are salvagable. Such a donor bike might only be worth $25, depending what is broken, etc. But a $25 Trek road bike would have to be in really sorry shape: lots of rust everywhere, missing or trashed parts, etc.

So its all in how much TLC the bike needs.

Note to sell on ebay or Craigs List, its not just putting the bike for sale, you need a high quality listing with great pictures. Otherwise, the prices will be even lower.