http://www.costcophotocenter.com/Help#/topic/terms-and-conditions
A credit card is required for Home Delivery of prints and other products. We ask you to provide a valid credit card number (including expiration date and billing information). We will only charge your card if you order digital prints, digital enlargements or merchandise from the site for home delivery. Please note that your credit card is charged when your order is placed. Home Delivery digital print and merchandise services are available only in the United States.
I. Terms of Membership You must reside in the United States and be at least 18 years old to become a member of Costco Photo. Costco Photo membership (referred to as "Membership"
is available to you if you submit certain requested information to Costco Photo, including (but not limited to) your name, Costco Wholesale membership number and a valid email address. In addition, by becoming a Costco Photo Member, you agree to provide Costco Photo with true, accurate, current and complete information about yourself when such information is requested by the Services (whether by questionnaires, surveys, registration forms or other informational requests).
We have a Costco about a mile from here and they have some pretty good deals sometimes.
The terms and conditions for the Photo Center, only says 'credit card' As far as I know they only take cash or their American Express. But their terms of the Photo Center reads to me as it is separate form their regular membership.
They do have this:
By entering and using the Site, you agree to the Terms and that you are bound by and subject to them. In other words, these Terms are a binding legal agreement between you and Costco Photo in which you promise that you will use the Site only in a manner that is consistent with the Terms. If you have questions about the Terms, please contact us at service@costcophotocenter.com . If you do not agree with the Terms, do not proceed to access the Site or use the Services.