There are some other possible problems, too.

If it has air suspension, make sure that it is all ok.
It is not cheap to replace.

The bushings (both front and rear) and lower ball joints
in the front axle may need replacement. The upper rear
bushings may be somewhat expensive as they come complete
with the arms. Look for uneven wear on the tires, that may
reveal problems in the axle support.

Make sure that the ATF oil smells fresh and it shifts
normally.

The EGR return pipe is almost always in the verge of fracture
and is laborous to replace.

Get someone who know how the car should look, sound, feel,
smell, and you can be more sure about the car.

O2-sensors may need replacement. Sometimes the only symptom
of faulty O2-detectors are very rare misses while driving a
properly warmed up engine about 80-85 km/h with very light
gas pedal position.