ASSUMING you want a solid driver: add up the costs to baseline with OEM Toyota parts and supplies: full fluid change for engine, coolant, brakes, clutch, trans/transfer & axles, full tune up (cap/rotor/plugs/wires etc), repack/reseal knuckles & bearings, grease driveshafts and steering... and probably some other stuff.
This is the starting point. once you do all of this, or really WHILE you are doing this, you may discover parts that need replacing: tie rod ends, knuckle bearings, driveshaft spider gears etc etc...
Once the truck is solid from all of this it should run on gas and oil changes (and other "regular" maintenance) for years.
Cost of the above? Probably a minimum of $600 if you do all the work yourself. If you have to start replacing worn out parts... maybe $2000 if nothing is a BIG part.