I've got one. I like it! Set up right it's capable of really nice work. They're really well engineered, well built machines.
The one in the picture is a Mark VII, made in the '60s. It's a quite different beast from the current Mark 7 (which is much more similar to the modern Mark 5 but with additional features). As NCPAPAOF2 says, they're priced all over the place. And the M VII is a little bit of an orphan and doesn't have quite the factory support that the M V has. Finding a buyer might be a little bit more difficult than if it were a M V.
I see you have a jointer mounted on the left side. Do you have any more accessories? Be sure to catalog and mention them when you list it for sale.
There are Shopsmith groups on FB. I'd suggest joining a few, finding a few similar machines to gauge price, and advertising it there. Cast the net wide. GLWS!