Hi Louise,
I bought my 2000My TD5 Auto just over a year ago after handing back my company BMW. She's now got 210,000km on the clock and I have had a few things go wrong but also a few things which I see as normal wear and tear.
1) Head gasket cuz the radiator was leaking & she overheated (poor maintenance by previous owner)
2) Front discs and pads (wear & Tear)
3) Fuel pressure regulator replaced (Wear & Tear)
4) Two PAS pipes burst on different occasions (don't know why)
5)New Radiator (old one leaked again 12months after being repaired)
Normal Servicing cost are quite high which I have done at a local indpendant due to a 2 year warranty on the car - Head Gasket and Radiator covered. However, when the warranty expires, I'll service myself which will reduce costs considerably.
The only thing to do at the moment is the injectors which are noisey and there is an internittent misfire (probably oil in harness).
I love the car to bits and would not want to part with it just yet. We've had great holidays out into the bush and when visitors come to see us from overseas, I can't really think of a better vehl to take them to the Kruger Park in!
My colleague at work has 2 Disco 1's and his maintenance cost over the last 3 years has been +/- R3,000 (£200) so they have been really cheap. He goes on expedition at least once per year as well.
In Summary, you pay your money, you take your choice. Personnally I would take the Disco II cuz it is a better refined car than the Disco I ( I worked on DII project at L/R before I moved to South Africa). We put a lot of effort into that car. However, there are a lot of electrics that can and do go wrong.