For what its worth I have a 328 about to be delivered with a sticker of almost $56k. For me that car works.
An earlier poster said it - its about what you want. And the price *does* balloon. I felt in LA traffic I was best served with a 328 as my average speed is - gasp - about 15 mph at best. Adaptive Cruise Control for the freeway. A lot of toys.
I have a great deal - pretty much at invoice or close. Buy rate, etc. December invectives. I'm happy in the mid-to-high 5's with a medium sized drive off (around $3k taxes title etc.).
With a stretch of 100 bucks and an EU I can't do I might be in an M3. Hugely different car. I need mine leased now for the write off and happy with what I ordered. I had an E90 335 and have read enough about the new 328 to feel its enough for me finally making 230 horses.
Make sure you aren't paying much over invoice on a 328. Keep your MF at buy rate. No additional fees and you'll pay for what you want - for me it was a fully optioned version of this car.