All the talk about supply and demand and capitalism always assumes a large numbers of buyers and sellers. It breaks down when there are small numbers of buyers and sellers, like in pinball. There just isn't the same competition for buyers and sellers, and prices can reflect this either up or down. I suspect in your case you have the machines priced spot on, and buyers are out there, but you are not getting to them. Those prices would be dirt cheap on ebay, and expanding to additional CL communities might help. I would post lots of pictures, accommodate shipping options, and make sure the machines look and play great. Also...patience.
If you were anywhere near Chicago that WWF would be MINE!
GLWS!