You'll find it hard to figure out the hybrid component cost because there is no non-hybrid Prius and many of the hybrid components are internal to Toyota so they can't be found elsewhere. The price you found for the battery (should be about $1900) is what a replacement battery sells for, not what it added to the MSRP.
What might help is to go to
http://www.toyota.com/ and look at a hybrid Camry. If you choose "build your Camry" you can build a non-hybrid Camry (be sure to include all the options that the hybrid Camry has) and then build a hybrid Camry. If you've done it right the difference should be about $500. Yes five hundred. You'll find some sources that say $5,000 or more, but those all take a base model compact car with no options and compare it to a mid-size Prius, usually with all the options you can get, but the standard setups are very different between the hybrid and non-hybrid so it looks like you're paying a lot for the hybrid components.