Cardstore.com has $0.79 Halloween & Thanksgiving Cards.  Use the code CAM2734.  This offer is valid through 10/31/2012.

They also have $0.99 Birthday Cards available (through 10/10/12).  No code is needed.  It looks like you will also get free shipping!

Here’s the info about free shipping:

“Receive free standard shipping on all orders when you select “print my return address” OR when you select “print my return address and recipient address” OR when you select “send me blank envelopes”. Discount applied at checkout. Complimentary shipping promotion is for USPS standard shipping only and applies to orders shipped to a location within the United States (U.S.A). Free shipping cannot be applied to orders shipped to international (non-U.S.A) destinations. Discounts applied at checkout. To prevent abuse, we reserve the right to discontinue or modify this offer at any time without notice.

OR

Receive free postage on all orders when you select the “Mail to the Recipient” option. Offer valid in the United States and US territories only. Discounts applied at checkout. To prevent abuse, we reserve the right to discontinue or modify this offer at any time without notice.”