Did you Google the parts for the lowest price? Often parts are available from China at dramatic savings. Example;
http://www.carparts.com/details/BMW/...B&gclsrc=aw.ds $30 each!
Did you pull and reseat the corresponding fuses? Whenever there is a problem with either of my BMW's I always try that and sometimes it clears the problem. Its worth a try.
If you do sell, don't trade in, you'll get much less. Sell it on CraigsList or Ebay.
I finally sold my 01' X5 4.4 with 235K on it and got a 13' X5 with a 3.5 with 35K on it. The technology improvements alone were worth it. I also purchased an aftermarket warranty for 5 years and 150K for around $3K. Good luck either way.