I found one in the Seattle Times the other day. he was selling it for $3300, I believe it was a 95 se-r. Minor front end damage, 90,000 miles.
I woulda bought it but there's no way I want an SR20 engine matched to an auto tranny... forget it!
Looks like you're a fellow Bimmer lover too. I'd be missing my M3 if I had one too. I'm dying to get an E30 M3 someday, but that's a little ways off. I'm just driving my clean little 320i. Can't argue with an 82 with 142k miles on it. Werks for me!
Happy hunting and let me know if you see any 91-93 Sentra SE-R's for sale.