Prices:
Cheapest package, $45 plus tax. Includes Hair, sash, button, princess keepsake bag, make up application (you get to keep all the stuff they use on the child), princess ring.
Next package: $50, plus tax. Includes all of the above, plus nail polish (and like above you get to keep the little bottle of nail polish)
No photos included though there us usually a photopass photographer there who is taking pics as the makeover is in progress. After the "unveiling" they will take your child to the backroom (where you can change first if you want) to do a special photo session with some props/backdrops and the "child sized Cinderella carriage". All photo packages are extra, starting around $40 IIRC.
IF YOU HAVE AN ANNUAL PASS, you can get a discount on the BBB. It is a MERCH purchase not a "service". Also, if you have a Disney Visa, and your purchase is more than $50 you can get a discount (hint hint, you can shop in the princess shop and try and ring that up with the $$44.95/$49.95 package and get your 10% off.
There are "higher" packages, called something like the Princess package or whatever, but basically it's the makeover plus the price of a dress, shoes, crown, etc and usually these are starting at $200.