The idea of one quartz crystal per frequency is as old as some of the earliest radios (think "crystal" radio set). And, yes, it was cheaper, at least at first but obviously very limited in functionality. Radio Shack carried all sort of crystal so that you could retune your police scanner based on your locale. As an aisde, my club has two Dittel base stations (battery and AC powered) that are based on panel mounted Dittel radios. One radio is an FSG60M which has a four channel "memory" manually set by some large rotary switches on the top. Never saw that before. You can see pictures of this radio at http://aviation.derosaweb.net/transceivers/dittel/.