They were Pioneer's cheap line when new.
I believe that you are mis-informed, sir.
The CS-R series was the
transition from the "traditional" Japanese speaker design with the beautful cabinets and wonderful lattice-type grilles that unfotunately didn't usually sound as good as they looked, to the later to come HPM series.
The CS-R 300/500/700 were the 3 most common models. The CS-R300 was a 2-way 10-inch system, the CS-R500 added a midrange and the CS_R700 was a 3-way 12-inch horn loaded system.
They were anything but cheap, as the CS-R700 was priced at somwhere around $500 a pair, and were positioned to compete with the JBL L-100.
Later, the HPM-100 would be designed to compete head-to-head with the JBL L-100.
You may be thinking of the "Project" series that were the "value leaders" for Pioneer at the time. These included the Project 60, Project 80 and Project 100.
The sound of the CS-R300/500/700 was as different as night and day from the traditional CS series. IMHO, the CS-R500 is the best sounding of the three, but the CS-R700 is certainly not to be ignored. I have a pair of each of the three.
Closely examine the attached information that is in post #6 and post #7 of this thread. :
http://www.audiokarma.org/forums/showthread.php?t=281969