The math here makes a flawed presumption: that you play a song only once after buying it from iTunes.
I obviously don't know your listening habits, so for you that may be the case. But people will listen to a single song far more often than once. Or otherwise there'd had to be 77.946.027 new users on spotify[1] last month all playing Ed Sheeran once. Clearly nonsense.
If you play every $1 iTunes song eight times on spotify, the costs (and therefore fees) will be on par: $10/month.
I obviously don't know your listening habits, so for you that may be the case. But people will listen to a single song far more often than once. Or otherwise there'd had to be 77.946.027 new users on spotify[1] last month all playing Ed Sheeran once. Clearly nonsense.
If you play every $1 iTunes song eight times on spotify, the costs (and therefore fees) will be on par: $10/month.
[1] https://open.spotify.com/artist/6eUKZXaKkcviH0Ku9w2n3V