I have the opportunity to buy a 68 coronet with a 383 and rebuilt automatic trans. It has new paint, exhaust, tires.....interior is a little rough. Asking price is $6000. I am not very knowledgable on the old mopar cars. Do the Coronets have much collector value and is this about right for one in the described condition?

Guess you need to know what type of coronet it is. 500, 440 or R/T. also if it is originally a BB car.
The R/T is the most desirable, and 6k would not be out of line. For the other two, it is a bit high unless all the body work is done and the paint is fantastic.
Most decient driving ones, hardtops that is, usually run in the 2-4k range. 6k isn't out of line like I said if the paint and body work is done well.

It is not an R/T. Paint and bodywork done is very nice.