The people who'd been using my apps for a while and still hadn't subscribed were never going to start a recurring payment. So this month I added a lifetime tier alongside the monthly and yearly options, just to see if a one-time commitment was a different question.
One person bought one. Not a flood, but a signal. A recurring payment asks "are you in forever?" A lifetime tier just asks "is this thing worth a fixed amount once?" Those are different questions with different people on the other side.
I'm now at $25/mo across all the apps, up from $19 last episode. Three months from now will tell.