I ordered a couple of boxes of duplicate checks from Costco. I don't remember the price, but it was the cheapest I found and they had a 10% off coupon code at the time. I notice that the checks I got are on cheaper/thinner paper than the checks that CitiBank sent me... but I don't care.
BTW, I figured out that you actually don't need to have a Costco membership to buy from their check supplier. If you enter your Costco membership number incorrectly like three times, the check site will just give up and move you on to the next page.
I know this because I have an international membership and the number doesn't work with any of Costco.com's online stuff.
Yeah.