I just purchased a 2012 Prius II for my sister from World Toyota in Atlanta for $23180 OTD (tax, title, reg included). This dealership does not charge a doc fee (which they told me was pure profit, a BS fee). They price their vehicles by how long they've been on the lot. The one we chose had been sitting there the longest (2 months), so it was around c.21750 before tax, title, reg. We added a rear bumper guard for $83. I negotiated the deal through their internet sales department in about 20 minutes, was assigned a number and given a guaranteed drive-off price. The sales manager called later and gave me his cell phone in case anything came up (I was driving in from North Carolina) I walked in the door with my number, was assigned a sales rep who brought me a cup of coffee, and got right down to business. I brought my own financing from PenFed and was out the door in about an hour - they did not waste time doing paperwork, didn't push extended warranties, just got my sister in her new car, explained their service plan (2 years free oil changes), and got us on her way. Overall, I was very happy and recommend this dealership. I live in North Carolina, but will probably fly to Atlanta to pick up my next Prius there.
Just an FYI, your sister has a Prius Two, Roman numerals were Bly used for model designation in 2010. Glad you got her a great deal and that she has joined the Prius family.