Durango:
Take a road trip to Florida (or insist that a Cali dealer find you a lower end car if that's what you want). I don't have the exact data at fingertips (I'm on a road trip and using an impaired internet connection...), but the Prius ranges in price from a low of about $23k for a model that is equipped similarly to something like a Camry CE all the way to just under $30k for one that's in "near Lexus" setup. Oddball add-ons by a dealer can drive such a car north of $30k, as can dealer greed. The supply of Prii is now increased (production finally increased) so the supply-demand balance is shifting favorably for the buyer.
Mike's comment about the Camry Hybrid is well taken. I would hope that as the model matures and more buyers appear, they will loosen up the model structure and options packaging. In the meantime, of course, the dealers will shed no tears about selling all those "extra" nav systems.
That said, while this is a tad OT, get the NAV anyway! I've become a believer. I have it in my Prius, and I got a $10 per day Street Pilot with my rental car I'm driving around the Pacific Northwest for the next few days. It has already saved my butt twice. Found the hotel last night with no fuss at all, and navigated from one side of Portland to the other, through territory I've never seen before, with complete ease. Time and technology are marching on -- these systems are getting phenomenally good.