I think this is an over-attribution of this cost. Even if you release the same app for nothing, and that cost went away, your overwhelming cost would still be your time, and the value of that time. $8.33/mo isn't even a rounding error in the grand scheme of things.
What it does do is pay for all the app store infrastructure, IDE development, etc etc, so your choice to release something for nothing doesn't externalise those costs on others.
What it does do is pay for all the app store infrastructure, IDE development, etc etc, so your choice to release something for nothing doesn't externalise those costs on others.