Here are the official ordering and pricing guides for the 2013 1 Series Coupe (E83) and Convertible (E88) [download PDFs below]. The pricing listed in the guide is effective July 2, 2012.
The 2013 128i and 135i models seen no change in price from the 2012 models (as of January).
The just announced 135is
model starts at $43,250.
Production of the 2013 1 Series will begin in July.
For a list of the July production changes for the F30, see the following info: 2013 BMW 1 Series (E82/E88) July Production Changes (All)
* Click to download 2013 E82/E88 price guide *
* Click to download 2013 E82/E88 order guide *