Audiomart days-
I think what we are witnessing IMHO is indicative of our new technology--the email buy. Our hobby is unique in many ways and for me the best experience is in conversation with fellow audiophiles. There is an understanding and respectfulness when meeting someone for the first time on the phone (Audiomart days). I am afraid its a lot easier to 'lead on' via email. Hard to know if the person is seriously offering or just picking your brain.
A one to one conversation will more likely result in a better outcome for both parties. Perhaps its best for those who are left with the virtual empty bag to start commenting via Audiogon feedback when a serious offer has been made and there is no valid reason given for the change of mind.