Pay per card, or Subscribe & Save!
On a per project basis Happy Donors cards range from $.99 to $1.74 per card, depending on volume (not including postage).
A monthly subscription gets that same pricing but at half the volume levels, and you can spread that volume out over a month of orders. The annual subscription is a further 15% discount off of the monthly plan price.
You can cancel or change at any time, and just pay through the end of the current period.