I used to sell peptide boxes so can speak to this. The margins were very good and demand was enormous. That may have changed since for most of that time there were only two of us doing it and we mostly tried not to make identical stuff. Demand dramatically exceeded my capacity to meet it; I probably could have charged significantly more than what I already considered too expensive.
I stopped doing it mainly because the writing was on the wall with a ton of people all starting to sell the boxes, and it took more of my time to manage the sales and do the work than you’d think. But if you don’t have a good paying job you can certainly make more selling peptide boxes and running group buys than driving for uber or something. That is unless all the new box makers have eaten each other and driven down the prices a ton, I haven’t really tracked the market.