Here are the official ordering and pricing guides for the 2013 3 Series Sedan (F30) [download PDFs below]. The pricing listed in the guide is effective July 1, 2012.
The 2013 328i sedan sees an increase of $1600 and the 2013 335i sedan will cost $400 more than the 2012 models. The new models will include the 328i and 335i xDrive models. The 328i xDrive starts at $38,500 and the 335i xDrive is priced at $44,800.
Production of the 2013 3 Series will begin in July.
Much more information inside.