you need to redo things and replace engines, gear boxes, some time twice and in my case some time paint it twice too
Agreed with bro issidique i personally lost the patience between my resto and gathered my energies after few weeks to start working on it again.
As far as money is concerned you should keep the budget of 600k to 800k approx for a nice fj
Points to be taken care of before buying an army retired fj:
The auction year should be the same of procurement year, as every passing month will increase the registration cost.
The engine should have engine oil and spark plugs placed on it as in many cases people have found water in engines which result into a high resto cost of engine.
Both drive shafts should be intact.
Model should not be older than 83-84 as older models came with 3speed gear.
Few more things like, rust, body parts, dash board parts, engine parts etc should be checked as these small items are hard to find and need alot of money if you want to resto it according to stock specs.
Good luck