There's no good way to determine value for a vehicle like this - there are so many factors it could range from a great deal to a money pit in-the-making.
As stated before - check for rust - if there is anything that prevents the vehicle from being driven that needs to be accounted for (engine, trans, xfer case, driveshafts, axles, hubs, etc.)
Is the speedo hooked up? if not, the mileage is another question...
Could be a great jeep if it's in running order without much rust - could be an adoption of an unfinished project otherwise.
My advice - if you're looking for a cheap jeep, you'll end up paying for it later - especially if you plan to trail ride or use it as a DD and it's got issues - if you want a CJ5, this may be worth looking into.