About 15 years ago I bought an '86 FJ60 just outside Las Vegas, NV. Rust-free body and frame. Had been sitting outside for about 7 years. Engine had thrown a rod as evidenced by the hole in the oil pan. Came with a clean '79 2F bare block, head, and crankshaft. Other than the 2F long block, was complete. The sun had done its number on some of the interior, mainly the vinyl door panels and one spot on the upper part of the passenger seat. Paid $1,200. A little while later I bought a running '89 FJ62 with some body damage in Santa Fe. Same interior color. It had about 145,000 miles. Paid $1,500. Including a rebuild on the 3FE, brand new H55f, OME suspension, clutch master and slave, new clutch, 70-Series Land Cruiser wheels, BFG LT235/85R15 ATs, R134 conversion kit, fuel pump, and a lot of miscellaneous parts I'll have a like-new FJ60 for about $13,500, about $1,000 less than I paid new for my '84 FJ60. Of course that doesn't include my time, I've been working on the build for almost a year and a half, and I've still got a ways to go.
Other than that I can't offer any insight into what a fair price would be these days. If you're willing to put the time into this it could work out well for you.