What I am (and others are) trying to say is if you are having to buy a high mileage example of a car to be able to afford it, you will have to expect the possibility of high bills.
Better to manage your expectations and get a lesser car with lower expected bills if the bills are going to be an issue.
What others are trying to say is there are cars that have been to the moon & back but been looked after that should be more reliable, and there are those that haven't been looked after & won't be reliable.
Either way, if you are only doing short journeys a large-engined turbo diesel auto with DPF is NOT the car for you whether it is AWESOME or not, and IF you insist on buying one you WILL have to expect some big bills unless you get a perfectly well looked after example that at least gives you a chance for a few years before it starts going wrong.
And now AAAHMOOT!