Cheaper alternatives for PayPal Adaptive Payments and Stripe

Question

I'm currently looking for a checkout provider for a marketplace app we're designing. I studied PayPal Adaptive Payments and Stripe and they do the trick but it are too expensive (2,9% of transaction). Who has an idea of making this work with other/cheaper solutions?

Our case: The users should be able to pay each other. When user A sells a product to user B, user A requests a payment from user B and user B pays user A. In their settings the users can enter their account number (so this may vary from time to time). Payment will made directly to the other user, without our intervention.

Answer 1

If you're selling digital content have a look at Google Wallet for digital goods. Base transaction fee is 1.9%.

https://developers.google.com/commerce/wallet/digital/