Carlos, I doubt I would pay more than $15,000 for it, if it checked out in person as good as it looks in a few photos, because I don't particularly want a 3-speed transmission and drum brakes all around. But it will probably sell for more than that, to someone who wants a '74 and/or doesn't care about those things.
What do you want to do with an FJ40? If you just want a cool old truck to drive occasionally on weekends, then the three speed and drum brakes won't matter. If you want one to drive very much/very far, then later models with 4-speed transmissions, disc brakes on the front, and (later still) 3.70 differentials are a lot nicer to drive (in my opinion). If you want to go off-road a little or a lot, then those would dictate some different criteria also.
How much mechanic and auto body experience do you have? You are wanting to buy a 40-55-year old truck; it will need a lot more maintenance and TLC than a newer one. Most of these have some rust by now, some more than others. Both mechanic work and body work will be expensive to pay someone else to do, if you can't do them yourself (or aren't willing to learn).
These are some of the things you need to think about before you can begin to make an informed decision on any Land Cruiser.
I am busy with family stuff right now (new granddaughter) but in a few days after everyone goes home, I can talk on the phone. Meanwhile, spend some time reading this several times over:
Buying a land Cruiser