Well, it's probably too late for this year, but I got 20 front-and-back cards from Snapfish on 100-lb paper for free (thanks to a code someone posted a while back on the Budget board), plus shipping, so a total of $6.35.
Then, I got another 10 from Staples for free, no shipping from a coupon they put out about a month ago when you ordered in store.
So, 30 cards for $6.35, and that just about covered my entire card list... I've been slowly cutting in down to save on stamps, etc. I handed out about 10 at Thanksgiving, again to save $. Sending out tons of cards really adds up. I got away for about $15 after stamps.