Is it ok to buy to 2003 bmw x5 with 190k mileage? What could be the possible issues and repairs at that point?

Ok *IF* - you have deep pockets! Expect high maintenance $$$

I have a 2002 x5 purchased in 2006. Still going strong and fun to drive. Leaks oil like crazy, but I'm carful to keep up on that. Annoying expense was replacing all the outter door handles that would break one at a time and the electric window motors. If I had it to do over again I would.