No Idea on the value, but there's a nice looking one on local CL, asking $450?
If it's in really good shape, that's probably a reasonable price. I paid $800, which is about twice what a good T-40 should be expected to sell for, but mine had an unusual combination of things that I'd been looking for that made for a reasonably rare instrument I wasn't likely to find again, along with the (hard to find) older-style OHSC in decent condition. It's not quite a museum piece like ggoat!!!'s, but I'm happy with it.