I'm an absolute fan of the 1006, 4506, 4566, 4566tsw and 5906 Smith's. Very dependable and I've never had one have any sort of malfunction, ever. I own 3 1006's, 1 BNIB, 4 4506's with 1 BNIB, 3 4566TSW with 1 BNIB, 2 standard 4566's both used and 4 5906's with 1 BNIB. Sounds like a lot, but they are rock solid, and plain fun to shoot.
As to pricing a 4506, a used one in good shape is worth around 425.00 and in great shape about 450 to 475.