About.com have put together another great collection of articles to help buyers in the used car market. How to Value a Used Car – [About.com] Private Party – The value a private individual can expect when selling to another private individual. Many consider private party values a baseline. Retail – The value a dealership or used car lot will assign to the vehicle. Used cars sold at “retail value” will often have been reconditioned, carry a warranty, or both. Their prices may be up to 20% higher than private party values.