Usually no ED discount for M3 -- that is a deal killer for me.
For me the comparison is:
36k E90 335 ED
2k Bilstein coilovers installed
2k M wheels and PS2s
2k Quaife LSD installed
.2k interior M parts
.5k sway bars, bushings
If I could get an E90 M3 for under 50k that would be a better option for me. But without the 5k or so discount below USA MSRP that you can get with ED and a bargain price (invoice + 1k), that does not seem likely.