[Salmoneye]

We offer a free membership that will allow you to bid on items right away. For security reasons, this option is only available to members who register with a paid, corporate, government or ISP email address. Members that use an email address from a company that offers free email addresses like Hotmail or Yahoo will be charged an activation fee of $1.00. Persons whose registration information is flagged as suspicious by our fraud prevention systems may be charged a $2.00 fee to go through a detailed security check.

SELLING:

To create a safe buying / selling environment, sellers must verify their identity with us. Sellers will be charged a verification fee of $2.00 to go through a detailed security check. This process is required in order to be able to sell. We reserve the right to deny access to site features if we are unable to verify your identity.

http://www.gunbroker.com/user/fees.aspx