if your talking anything 2000+ for a 3 series, mint. less than say 45k miles.
expect around 26k for 325 and more around 28k maybe 30k even for 328.
also depends alot on what options are installed, but my 03 325i was 28,400 with 12,000 miles and the factory installed performance package.
<img src='http://www.bmw-forums.com/forum/uploads/post-46-1095116979.jpg' border='0' alt='user posted image' />
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