Im in the same boat as the OP. Looking to replace the e92 335i this upcoming spring with an e90 M as I cannot stand moving the dang infant carrier anymore for my 5month old and it will only get worse with the car seat.
I actively check each week on pricing and there are plenty of e90/2 M's in the sub $35k range for '08/'09 MY. I've even seen a few bare bones '10s.
Keep us posted Malter when you do find the right one!
07 E90 335i TiAg