Purchasing credits with Paypal Pro

Any thoughts on purchasing bulk credits with the in-site credit card form? For some reason, my subscription level upgrade form uses the in-site credit card form. However the if they choose to click on bulk upgrade, they are asked to pay over at Paypal.

Also is there a workflow that would enable me to allow users to upgrade and not sites. I would like a user to enter their payment info and create a subscription, and then just be able to create X number of sites under that subscription. Upgrading each site separately is not really useful for what I am trying to do. Interested in your feedback on this.