In 1985 I shoved quarters into a Gallaga machine, one after the other, without a second thought. Now, even though apps offer unlimited play, like the author, I'm hesitant to pay $1.99 for one.
It was all incredible then and there was a value to the experience which is far cheaper these days. Further, you are fearful of getting suckered into something that's a thirty second glance and which you realise is rubbish. The 'desktop' real-estate on the phone is precious and you don't want it to be cluttered with rubbish but on the other hand once you've paid for something you won't get rid of it because you've paid for it.
what if you paid a quarter to buy it and then every time you lost, you had to pay another quarter with the new in-app purchases, just like an arcade game? if you beat the game on one quarter, you'll own it and not have to pay any more. if not, eventually you'll "put in" 8 quarters and own the game.
For some reason, I find "4 quarters" to be "cheaper" than than "$0.99". Maybe it's because I associate quarters as disposable and any dollar amount in $x.yz format to be more significant. I wonder what the effect would be if in the App Store a developer has the option of pricing the game as "4 quarters".
It could be the same illusion that $99 seems so much cheaper than $100.