There are many options in paying for coins in auctions
Proxibid mainly uses the Auction Payment Network, but sellers do not have to subscribe to the service. APN is a safe way to bid, offering security options that other venues lack. When an auctioneer uses APN, the credit card on file with Proxibid is charged after each session.
However, not all Proxibid sellers use APN. Here's where it gets risky. Some sellers ask that you contact them via telephone or (yikes!) email with your credit card number, including expiration date and CVC code (the three numbers on the back of the card).
Some bidders realize this too late because they failed to read the terms of service. Once you phone in or send your credit card information, there is no way to tell what the auctioneer will do with it. Perhaps the company stores it on a computer that other employees have access to, or worse, that can be hacked.
As a rule, I never call in credit card information. If you learn about the payment option too late, call the auctioneer and ask if you can send a personal check or bank check. You'll likely wait longer for your coins as sellers must wait for checks to clear.
Some Proxibid and most eBay sellers use PayPal, another secure way to send funds. PayPal likes to link directly to your bank account, and in that case, you're not getting reward points for using your credit card. Think about that. If you win a $20 Saint-Gaudens gold coin at $1,700 with buyer's fee, you just lost $17 or more.
Also, if you link directly to your bank account, and something with the sale goes wrong, it may take up to 30 days for the funds to be credited to your bank or PayPal account.
PayPal does allow you to link to your credit card if you want to claim reward points. There is no charge for this. Again, if a sale is canceled, you'll have to wait a month for accounts to be settled in your favor.
Auctioneers hate charge-backs so do not use your card to do that unless you have a real dispute, such as purchase of a counterfeit coin. You can be looking at extra fees if you attempt to cancel a transaction due to buyer's remorse.
Finally, always read the terms of service before deciding how to pay for your lots. You can save yourself time and, most important, money.