Back then, Edmunds published "price books" which were available at some newsstands back then. Had retail and dealer pricing of the cars and options for all US cars and trucks, usually. I used to buy them when I could find them. They've been archived for several decades now. Only thing that was not in them were the transportation costs, which allegedly could vary.
The Data Books are extremely informative! Almost every spec on the cars. Option codes, equipment levels for the various models, even some engine specs. Plus mention of the many engineering attributes of the cars, too.
Enjoy!
CBODY67