Pet prescriptions through Costco can save a ton of money too. My wife says she saved about $100 on the heartworm and flea and tick medicine for one dog. Definitely check it out if you have pets.
Y'all did convince me to get the Costco Credit Card after looking into the cash back %'s - it's superior than any of the other ones I have and with our recent shifting of most of our purchases to Costco, it's going to be a big W for the family.
