Are you curious about the actual price that the builder sold their houses? Or what your neighbors paid? This is all public information and all you need is a browser.
Go to http://assessorparcelviewer.saccounty.net/jsviewer/assessor.html# then search for your parcel number. The Retreats West parcel is 073-0900-023-0000.
The price you see includes the base builder price, plus any options included in the sale price.