No, this is incorrect. Google requires that you use their payment system (which takes 30%) [1]:

> In-store purchases: Developers charging for apps and downloads from Google Play must use Google Play’s payment system.

> In-app purchases: Developers offering products within a game downloaded from Google Play or providing access to game content must use Google Play In-app Billing as the method of payment.

> Developers offering products within another category of app downloaded from Google Play must use Google Play In-app Billing as the method of payment

The only exception they allow is if you're selling physical goods (which is the same as Apple's policy).

[1]: https://play.google.com/intl/en/about/developer-content-poli...