alt Hacker News> why should it scale
Because you need your business to be big enough to pay your bills, not just theoretically net positive.
I have made some designs that I thought of selling too. For something like that to work, you need thousands of customers over the time.
It's ok to spend an year or two of weekends working into something that can replace some of your main income. It's really not ok to do that for something that can't.
It sounds like you're wanting the the side-project to take over and replace your day job. Which is fine, but different from what I've been picturing for myself. Nevertheless, with that being your target: suppose you've grown big enough to pay the bills. Does the business still need to scale?
I see that as a bit of a trap, because people pass on what (to me) seems to be fulfilling work that could support a modest lifestyle and make big-growth choices that either crash them out or saddle their business with debt its market can't sustain.