I bought my first stereo in 1972 and by 1975 I was working in a high end stereo store. Back then FM was a serious source of high fidelity. AM was for top 40, FM was for classical, jazz, and album rock (with the same high standards of dynamic range and frequency response) was just getting underway. Saul Marantz's very first product was an FM tuner. It was so expensive that his first customer was an Arab sheik. In 1975 the Sequerra Model 1 Tuner came out. It was the first frequency synthesizing tuner and its 1975 price tag was $2500. That's over $10,000 in today's money. Could you imagine paying $10K for a tuner today?
The abundance of quality FM is one reason that a reel-to-reel deck was an essential component of the serious audiophile. It represented a serious investment. The mid-level R2R's of the mid-'70s were around $350-600, which is $1800-3100 in today's money. One purpose was to record when an FM station was broadcasting a complete opera, symphony, or the latest prog-rock album. Many people amassed libraries of such broadcasts. Another reason was to enjoy complete albums without having to flip the record--like for parties and lovemaking.