To find what the actual MSRP is of a Prius in your area:
Use a flash-enabled web browser, and go to:
http://www.toyota.com/prius/
on the left-hand side, under "SHOPPING TOOLS," is a link for "Build and Price Your Prius" where you will have to fill in your ZIP code.
It is here that you can find out what packages are available in your region, what the MSRP is for the Prius with those options and also for any Toyota accessories. Anything else is just something that your dealer has added on (for profit).
For fun, I used 06340 (Groton, CT). 3 options available.
Base price: $21275
DPH fee: $540
Option Combination A = package 3 BI = $1100
Total before accessories: $22915
Base price: $21275
DPH fee: $540
Option Combination B = package 5 AI = $2190
Total before accessories: $24005
Base price: $21275
DPH fee: $540
Option Combination C = package 6 BC = $5065
Total before accessories: $26880