I went by the BMW dealer and the recall is not for the X5 but the X3. I don't know what exactly is going on but that is all I've heard.

As for the X5 alone.
I had mine now for about a 100K miles and I will agree with others.
At ALL COST, you must do a pre purchase inspection.
In the last 3 years of owning the car I have spent about 7K on maintenance, and this does not include the other 4K I still need to spend on the valve seals.
I do have a 4.8 car but you should expect similar maintenance if you are not car full.

Good luck to you, if you get one post some pictures.