Ken:
A full registration will get you access to all the activities at the event, including the speaker talks on Friday, Saturday, and Sunday, the vendors selling in the speaker room, lots of raffles from our sponsors, the Rare Fish Auction, and the marketplace on Sunday. The auction is only available to folks you have registered for the entire weekend. It's one of the benefits of registering.
Club membership and registration for AquaMania are separate things, so, yes, for both you and your wife to attend the auction would be two full registrations.
Your full registration will entitle you to access to the marketplace prior to those with a Sunday only registration.