The only difference between an R-code and a Q-code is that the R-code is the Ram-Air (shaker) setup and the Q-code uses a conventional air cleaner. Otherwise, both engines are identical as long as you compare CJ-R to CJ-Q and SCJ-R to SCJ-Q.
Q-codes can, in some cases, command higher prices than the R-codes. My old Q-code, 4-speed
car brought $40K in December 2002, which was a much higher price than many R-code's were bringing at the time. Generally, the only ones selling for more were concours R-code's in general or comparable R-code, 4-speed cars.