Ability to store credit card information, so donors/bidders can provide their card at the beginning of the event, and have it charged for other purchases - not just for bidding/won items.

This would allow donors to have a "tab" where drink items, paddle raise pledges, live-only items winning bids, and more could be added to their credit card at the end of the night by admins, and without running a card (or running a second/third time).