In the heyday of film SLRs and prime lenses - say the late 60s to early 80s - the kit lens that most people got with their SLR was a mid-speed 50mm, like 50/1.7 to 50/2 (In the 60s it was sometimes a 55mm). By the 70s/80s, the most common wide and tele lenses that the advanced amateur got next were a 28mm and 135mm, at f/2.8 to 3.5 (typically most people buying an SLR and lenses were somewhat "advanced" in their interest - if you weren't, you had a fixed lens 35mm or Instamatic).
I don't know why those focal lengths became the most common. I suspect that the 135mm was just long enough to do telephoto things like take pictures of your kids playing sports, or animals. Slightly shorter telephotos like 85-105mm are great for portraits / headshots but that was a more specialized application. Lenses wider than 28mm were surely more expensive to design and make. Generally, speaking anecdotally, many people find that even basic 3rd party 135/2.8 lenses from the 1970s are decent quality, while early wide angles tend to be more variable; the wide angles probably needed more improvements in design and manufacturing to catch up.
Of course faster lenses always cost more, with more expense in design, glass, and tighter tolerances in manufacturing. This meant that for example an 85/2 was always more expensive than a 135/2.8, and it had less reach for Mom or Dad taking pictures of the kids' soccer game, so fewer sold, so they're more expensive today. Here's a link to the B&H ad in Popular Photography in Jan 1981:
https://books.google.com/books?id=r...ular photography&pg=PA154#v=onepage&q&f=false
You can see that for ex the Olympus 85/2 was US$215, the 135/2.8 was $150, and the 135/3.5 was $89. Unsurprisingly, there are a lot more 135/3.5 around now. US inflation is a factor of 3.4x from 1981 to now, so that 135/3.5 price is US$300 in today's dollars - good to keep in mind the next time someone complains that film cameras and lenses have gotten expensive.
