Well, you're jersey and I'm jersey
, so here are my thoughts:
I've been looking for a 2nd car to go tracking with, and the e46 has been on my radar. I don't think you're find a good car for anywhere near 15k, even on the 2001 (first year models). I think you have to wait a bit more for prices to fall on the e46 to get one near the 15k range.
You are in the range on e36 M3s and there are a bunch to choose from way under the 15k range. So if you are set on a e46, wait. If you want a car now, look at the e36 models.