Assuming you visit and inspect the 2006 with a OCR while asking questions (and not getting answers) regarding leveraging the 5 fixes (that are so well documented here)......I.would consider offering the private owner 5,500. The mileage should not be a red flag.

the dealer is asking way too much.

the money you keep in your pocket can easily pay for the next 2 or 3 years of enjoyment. And just around the corner is enjoyment.