I've got an old copy of the Roadrunner/GTX databook and price guide for 1967-1980. In it, I looked up pricing for 1972's more popular options for the RR/GTX line. You can get that info in this book but from what I've been told this book has been out of print since the early 90's.Price and production data as well as performance data are listed. I find it useful. You could also try searching MyMopar.com for reference tools on your vehicle.