Where do you live? The market pricing on SS/FG bikes really varies by location. Start watching your local C/L and you will become an expert on pricing in your area in a few weeks.

By local, you need to consider any C/L within about 100 radius of where you are located, plus C/L where you have family/friends that might be willing to pick up a bike for you.

Be prepared to pay full market on Craigs List. Most "deals" have issues that if you are willing/able to fix, can make them better deals. But clean, well maintained, and ready to ride bikes usually go at or near full market.

The harder you look, the better deal you will get. There is no free lunch on buying vintage bikes.