I bought mine 2 years ago with 90k. Highly recommend a pre-purchase inspection if you are not familiar with the car. I did and they found that both front axles were bad (could hear the clunk in tight corners), leaking PS hose, recommended flushing the auto trans, and a few other small things. Worth the $135 I paid. Gives you room for negotiations.

After that, first 10k were pretty uneventful, but it seems right at 100k everything started to break, as follows:
- Entire cooling system had to be replaced (started with cracked expansion tank)
- both front axle boots
- drivers door handle broke inside door
- rear window regulator
- all coils and valve cover gasket
- several cracked vacuum hoses under intake manifold gave me engine codes
- secondary air pump and valve
- brake rotors and pads

So, if the X5 you are looking at still had the original cooling system, it will cost you at least $2k to have that done within the next year. Everything else I have done by myself, but parts alone cost quite a bit.

I love the car, but maintenance is not cheap. Keep that in mind, and you will be happy.

Dieter