I'm okay with paying 30% where the return on investment is worth it. Both the Appstore and Google Play do literally nothing for you, except distribution, and payment processing. These really don't deserve to take such a big cut, and I don't really want to hear any more excuses in their favor
This is not about the App Store service's quality, this is about option. They could charge 50% for all I care, if we had the option to buy iOS apps from another store other than Apple's.