I've never owned a P38.....wanted to but warned off by so many people i actually took advice for a change.
I've owned my TD5 for two years, paid the right price and expected some issues. Done 20,000 miles in it, now at 90,000 and this is the list;
Fuel Pump - a regular problem I gather but easy to sort and under £200.
Engine Loom - Not just the injector one, I had to change the whole thing because of oil, about £300 from memory. An extreme case.
ACE Pipes - Ouch! I got a LR specialist to do it, about £400.
That's it other than normal servicing and tyres. I think it's a great car and it still looks good value, I'd certainly buy another. As usual, buy the best you can!
Good luck.