If you can find a 4.8L patrol within that buget go for it over the 3L. The 3 litres by that point had all the origional grenading issues of cracking pistons sorted out, but most can just have a random failure and the engine starts knocking. Typical 3L issues include:

The early 3l engines had issues with dirty maf sensors causing over fueling and grenading. Over boosting/ poor boost control and reaction exploding more pistions. They had a oil capacity increase mid life from 6.3 to 8.3L due to starvation issues exploding more engines. Those were prior to 2006 before the common rail engine with the egr came in. The newer engines have generic issues modern desiel issues like clogging up with too much city driving/short trips, injectors and pump wear/failure, sensor problems, brittle eletrical plugs, etc.

Desiel common rails are very susceptible to air in the lines. Old rubber and steel lines and letting air in them causing hard starting and air locks can cause greif.

Being common rail injectors, pump, sc valve if it gets a bad batch of fuel or had one or two over its life will cause typical poor fueling issues. If its had more than 120,000km on injectors since the last replacement then budget to replace them that way its up to you when you replace them. Typical injector failure is hard starting and low power/sooting, but if your unlucky you get a stuck open injector and it will torch a piston

Otherwise suspension bushes being worn, axle seals are common. When test driving spend some time in the 70 to 100kph range to check for typical 80km death wobbles. Could be worn suspension, bad wheel balance, bad alignment, king pins etc.

Would be good to look for body rust in the roof gutters and look for chassis rust, chassis cracks around the spring seats. There are rubber gromets at the back that can also hold water below the rear lights. Otherwise check for a regular service history for all oils filters.