Many things impact vintage bicycle value and some of them have nothing to do with the bicycle, itself. If you take the time to have a look at Vintage Bicycle Value, you will come to understand that things like size, location and time of year are among those things that impact final value.

And, as has already been mentioned by others, pictures and a more complete description (size, condition, etc) will help get you more accurate appraisals.

Hope this is a help.