My feedback from using Aucion Plagin,
Overall, this plugin looks nice and is quite functional. The biggest drawback is the inability to transfer payment from the buyer to the seller via credit card, PayPal or other automated transfers when Auction is finished. In addition, from the logged-in user level, you cannot delete outdated auctions. Only the admin can do this. This is weird.
Connecting this plugin with Pay Payment does not change anything regarding the payment for the auctioned item.
These limitations weaken the functionality of this plugin.