In 1960, UK, the "expected price" for a just released to-be-hit Pop LP was 34s1½d, while it's 7” 45rpm singles would cost 6s4d. In other words, you'd be able to buy 5 singles with the price of an LP.
Today, a 7" will cost you 7 to 12£, an LP 15 to 18£.
It wasn't the 'single' that was valued (on the contrary, it was devalued to 1/10th the album price, if you go digital), but the physical format.