What exactly is wrong with it anyway? Unless there is a burnt out PCB (board) in it, then it can be fixed pretty easy.
Look, you have many good options other than putting some crappy aftermarket antenna in.
1. Buy a rebuilt used one from junk yard. Check here:
www.car-parts.com
2. Buy a new original one from here:
www.antennaworld.com
3. Buy a direct replacement version. Look here.:
http://www.hirschmann-usa.com/aa/amfm.asp#1.4
Once you figure out what DSP version you need, do a search on the net for best pricing.
4. Open it up and see what's wrong with it. You should be able to put power to it to see if motor is fine. It may just be a belt.
And there are many other sources of info for antennas.
Also, if your antenna is "phone" capable and you are not using that capability, replace it with a non-phone version.
DON"T GIVE IN JUST YET!!!