Let Customers Pay What They Want With WP ieCard - Pay Your Price
WP ieCard - Pay Your Price is an extension of WP ieCard - WordPress eCards Plugin.
The Pay Your Price plugin lets you be flexible in what price you are willing to accept for selected ecard. You can use this plugin like to accept donations or to take a new approach to send eCard.
You can suggest a price to your customers and optionally enforce a minimum acceptable price, or leave it entirely in the hands of the customer.