Earlier quoted context omitted.
> As such, anyone with two brain cells to rub together will immediately outsource money handling, which means that your minimum price is now limited by how much your processor charges. Which should be significantly less than a dollar for small charges. Processing fees get in the way of charging a dollar each month, but they're perfectly compatible with charging $5. And that $5 could be for multiple months.
A payment processor generally also charges something simply for usage of service. And, even if they don't (and I'm having trouble thinking of any that don't), you almost always need a full time programmer supporting your monetary transaction flow. Sure, supporting that overhead doesn't matter if you have a million transactions a month. If, however, you only have a hundred transactions a month, a salary of $120K per y…
And as you say, there are services that handle the entire shop process, for a few more percentage points or a few hundred dollars per year, whichever you prefer.
If someone is charging ten dollars a month, it's not because of how much payment processing costs.