Keep the M believe me you will miss it. I had 2 face lift E46 M's, recently sold with 49000km.
motorplan extented to 2012 dec.
I looked around for 3 weeks, the 2004's or later are selling full retail even with 90 000km. I got almost 40k more than retail for mine.
I settled for a new 135i, i know after a while i am going to say "its not an M".
Well i couldnt afford a new M3, hopefully someday
if you not fussed about memories, then sell now and make good cash...