When a normal end user purchases a $10 Cadpage subscription through Google Play Store, we get $7 and Google collects $3. That sounds like a pretty stiff surcharge, and it is, until you realize that Google built the entire Android phone system infrastructure that we are using to deliver this cool functionality. They are entitled to a decent return on it.
When we set up alternate payment channels, like PayPal or personal checks, we avoid paying Google's 30% transaction fee, which is something we really aren't allowed to do. We have told Google what we are doing and why it won't work to route your payments through their system and offered to pay the 30% fee on the funds we collect. We have not had a response from Google.