OK, its a 97 with lockers, 64k miles, and dealer wants about 20k - right? Others are saying thats too much money, and to back it up, they tell you how much less they spent to buy a truck with close to twice the miles!
Well, you are going to find out that locating a 97 or earlier with lockers, low miles, and in very clean condition is likely to be a challenge. There are not a whole lot of them left. If I were buying I would pay a premuim for that truck. When you look at what you will finally end up spending on a Land Cruiser that you take offroad (maintenance, gas, sliders, front bumper and winch, rear bumper & tire carrier, on board air, cb, taller springs, new shocks, yada yada yada) an extra grand or two to keep the dealer rolling in the dough is no big deal.
The way I look at it, all I get out of any vehicle is miles. Presuming the condition is good, the lower the miles are when I buy, the more I miles I get out of the vehicle, and therefore the more it is worth to me.
You can spend the next couple of years looking for a great deal for a good truck. Meanwhile the age and miles on the fleet keep going up. I think you may have already found the good truck and I'll bet a few of the readers on this site are already reading through the Chicago used car adds looking for your dealer!
A prepurchase maintance check that you should perform is to drain enough coolant from the radiator so that you can see the top of the core. Check the tubes for gunk that looks like grey mud. If the radiator is gunked up then it is time for a good engine flush, and a rodded out or replaced radiator. There is a drain plug on the lower driver's back side of the radiator. It is surrounded by tranny cooler lines so is hard to see or find, but it is there. Gunked up radiators are one of several quirks that some Land Cruisers have. I haven't come across a definitive reason - some say its left over casting sand, others say its from mixing incompatible coolant, etc. Whatever, check for it before you buy. I would expect the dealer to eat the cost of a radiator replacement if a visual check shows it to be clogged. The radiators are big enough that even a partially clogged radiator keeps the engine cool under normal conditions. Meaning a highway test drive, even for hours, won't necessarily show any problems.
Rich