Worth $700.00??? Hard to say, sight unseen. If all you want is a wall hanger, still more than I'd be willing to pay . . . haggle with the guy. I bought a wall hanger for $400.00 and decided to fix it up and now it's a shooter! Down the road if you start thinking to make it a shooter, the cost of parts alone will bring you way over the $700.00 Just my opinion!
If you're looking for a shooter, try Shiloh Relics online or Dave Taylor's Antiques online . . . I'm not connected with either, but they seem to have a good selection of Spencers from time to time.
Two Flints