If it's any comfort, I made that calculation and decided not to sweat it, but purchase any app costing less than ~10 with about as much thought as I'd give to buying coffee.
I feel similarly, if I see a mobile app that I think might solve my problem and it's low single digits, it's practically an impulse buy. If it doesn't work out, I don't feel used.
I've also happily spent $15 on an iOS app before because it was really good at what it did.
It made me wonder if there's a really great market out there for an incredibly well done niche mobile app you could charge $99 or more for. A whole lot of customer service problems disappear when you preemptively disqualify the uncommitted...
Some of the apps put out by the Omni group fall somewhere in that ballpark depending on which edition you purchase.
If a product is truly top tier, I’ll definitely consider paying a higher sum. I’ve sunk plenty into the Omni* suite over time (although I do wish they’d iterate a bit faster on OmniFocus…Todoist is pulling ahead, but I digress).
