One thing about prices in the early-70's that should be kept in mind is inflation, especially with respect to european currencies, was roaring during this period. I think many prices doubled (and more) during a 5-yr period eventually paving the way for Japan's displacement of europe. Thus, comparing prices of a 1968 PX10 with a 1970 Fuji Finest with a 1973 Grand Record without adjusting for inflation can be very misleading.
Jack Romans (1970: 4 DM = $1US)
Sacramento, CA