Really? I just looked at all 30 on my list and they *all* had make offer buttons. I always assumed the one or two I've encountered had been sold since I brought up the list, when I refresh it, they are gone.

Perhaps it is a bug/glitch that I have not seen ..Whenever there is a unexpected action in the game take a screen shot, this helps if later you have to request support and on here to show exactly what's happening to you. Also, always a good idea to clear Flash and browser data and refresh the page.