There are several variants of Krytox lubricants. Some are widely used and are available in small quantity, some are not. If purchased in small quantity, say 1 oz, shipped price is close to $40, which I think is prohibitive for many people. If purchased in larger quantity, it is still expensive. 500g container goes over $200.
I didn't start my lube journey with Krytox. I tried to explore with cheaper alternative first, but after I experienced Krytox, I didn't really feel necessary to look at any other lube. It was that good. I tried superlube, some lube that I could get for cheap at Home Depot, reel oils, and etc. First, they weren't good enough (that is why I continually searched for alternative and began spending bigger $$ on lubes). Second, safety on rubber and plastic were not guaranteed for the cheap lubes since they lacked proper documents(spec sheets and etc).
My initial search for lube was intended to be used on my aging HHKB, so it had to be rubber and plastic safe. Krytox was well known lube solution for Cherry switches among Korean community, yet I didn't know how to get them and I was hopeful that there were good enough alternatives hence my search began. There may be cheaper and equally good solution, but I quickly learned from my search in cheap lube that cheap solutions don't usually work as it should. I am not an expert in lube by no means, so my search in consumer level lube may have been bound to fail and Krytox is probably an overkill. I just don't know of good enough solution that performs as well as Krytox in keyboards though. If I knew I would have recommended them, but I can only recommend and compare the lube that I have experienced and tested.