$1/day forever is around $9125 using the safe drawdown rate of 4% per year.

So if you’re a bakery and a customer offers $9000+ for a fresh roll every day forever, you should almost certainly take them up on that offer. A smart baker could probably get that number sub-$5000, but you’ll always come out okay around 25x the yearly cost (in this case, $365).

Similarly, if the amortized yearly cost of a customer is $12 (ie, $1 per month), then a $300 forever price is financially indistinguishable from a permanent subscription. (Actually, better: time value of money, they can’t cancel the annuity you buy, etc.)

So there always is a price where that is financially viable.