My family was literally the first in town to own a VCR. This was in 1979, well before video rental stores started to appear in our area. ...And indeed, a blank tape cost about $20 and a prerecorded tape of a reasonably major motion picture cost about $80. We had a Toshiba Betamax-format VCR, BTW.
"Everyone" always said Beta was superior, but the only "first-hand" source I ever saw was a Sony advertising poster, though it mostly tried to demonstrate how U-load systems (such as Sony's Betamax and U-Matic) were better than M-load systems (such as VHS). Apparently this advertisement or one like it was the germ of this "Beta is better than VHS" trope.
I have a few early VCRs in my collection, and I can vouch that early VHS machines tend to have "clunkier" load mechanisms than early Betamax VCRs, and this would be much to do with the M-versus-U loading mechanism. I would also not be surprised if a first-generation Betamax VCR using the original Beta I speed (which was quickly discontinued in favor of the slower Beta II speed) offered slightly more resolution than a first-gen VHS machine on SP. However, VHS-format VCRs got better rather quickly, and I doubt that Betamax had any visual advantages over VHS once you got to the early/mid 1980's.
Besides, back in the late 70's when these new-fangled home VCRs appeared, people didn't have TV sets with composite inputs and comb filters, since there was no real prior need for the former and I don't think the latter existed yet. They had sets like our then-new 25" Zenith System 3 console with only an RF input and no special video enhancements. Even if there was a difference of 10 or so line-pairs of horizontal resolution, it'd be negated by the consumer TV technology of the day.
By the way, while maximum runtime was indeed a big part of the picture, it's interesting that VHS originally got longer recording times not because JVC was particularly interested, but because RCA (which was in the process of getting VCRs OEM'ed from Matsushita (Panasonic)) insisted on having a longer running time than 2 hours on a T-120 tape for the American market, so they and Matsushita came up with the "LP" speed. JVC never really endorsed the LP speed, but they then started adding the even slower SLP (later known as EP) speed to the format.