Spotify have the exact same pricing model/discrepancy http://thenextweb.com/insider/2015/07/08/spotify-is-actively...
But see, I was an iOS user paying $10/month for Spotify (because I paid on the web). Does Soundcloud offer this, or is it truly every iOS user has to pay through Apple for their subscription to Soundcloud Go, and thus have no choice but to pay more? It seems like it's the latter by the wording of their copy.