We're in the process of building out a BuddyPress/Multi-Site membership network. We're utilizing the Classifieds plugin for our members, but we want to use the credit system as these will be add-on purchases apart from the main membership costs. As it currently work, users can post classifieds without needing any credits. It also doesn't appear as though credits can actually be purchased on the buy credits page. It does show the option for both PayPal and credit card purchases, but both return an error when trying to purchase them.
On a side note, is there any plan on when the Authorize.net option for purchasing will be implemented? PayPal is fine for now, but eventually we want to be able to use authorize.net for everything.