This is what has gone through the auction for 2011 e92 M3's (not sure where the May sales are) Not that a dealer has to give you this price, but it shows you what they are paying for them at auction.
04/17/12 ORLANDO Lease $56,400 16,444 Avg ALPINE W 8G 6 Yes
04/18/12 NJ Regular $51,750 16,910 Below Blue 8G M Yes
04/19/12 RIVRSIDE Lease $56,000 8,886 Avg JET BLAC 8G A Yes
04/19/12 RIVRSIDE Lease $54,000 30,685 Avg MINERALW 8G A Yes
04/24/12 ORLANDO Regular $58,000 946 Above BLUE 8G 6 Yes
04/30/12 EL PASO Regular $57,300 10,239 Avg White 8CY A Yes