IMHO...
*I think that one at the car yard is a bit over priced with 200K.
*Buy the newest year model with the lowest km's you can find.
*In the ideal world one with low km's and serviced every 10K, the 24K servicing is crap regardless of what people will tell you.
*There are still some very low km's D4 3.0lt around you just need to look hard and expect to pay premium dollars, but still way cheaper than a used same year model Land Cruiser 200 series.
*Its a better 4x4 on road and off road than a 200 series.
*D4 3.0lt I say are no less prone to failure than a D3 but with less options to repair.
*Consider new 3.0lt engines pretty well unavailable now and just to get one landed in Australia is likely to cost round $30K (then there is labour to fit)
*A used engine will cost round 10 - 15K if you can find one.
*Inlet manifolds are prone to failure.
*Oil coolers are prone to failure.
*electronic park brakes are prone to failure and are no better than old D3 models.
If you find a good one, then initially your service costs are:
*engine service, driveline fluids changed, auto serviced.
*timing belts AND top coolant outlet change.
*If a 2015/2016 with round or under 80K get the top coolant outlet changed.
*If its had the timing belts changed by a dealer then get the top coolant outlet changed.
*front lower control arms are a common item (anything with independent front end).
A D4 3.0lt would be the last Land Rover model I would ever buy (besides a new Defender).
From the newer vehicles I see the build quality hasnt got any better.
I see plenty of D4 models with good to really good service history that are into the 290K plus and some or none of the above have failed.

