[jetpacktuxedo]

I mean it isn't like any of these makers are sharing their tax returns or anything, but for example eat_the_food is the designer and manufacturer behind "Nightcaps" [0]. He ran an event called "Poisoned summer" where he had 80 days of "micro batch" sales, where each sale was for somewhere between one and fifteen or so caps, priced between $60-80 each. Most days the sale was only open for about one minute, and in that minute he would have hundreds of entries to randomly draw "winners" from, and then the winners would get to buy the keycaps. I'm pretty sure he hit six figures in sales on those 80 days of sales alone, and those were not his only sales throughout the year. He isn't even making keycaps full-time yet, he still has a day job.

Several other members of the mechanical keyboard community (especially in the artisan keycap subsection of the community) have managed to turn their keyboard hobby into a full-time job and make a pretty decent living out of it.

[0] https://geekhack.org/index.php?topic=79513.0