Why not put your design together and put it on a site like Zazzle, CafePress or Wordans. That way you don't have to worry about minimum orders -- or for that matter, about anything at all.
Though the "One more thing" slogan is probably outdated at this point since Steve hasn't really done a "One more thing" in a while and it's no longer as ubiquitous as it was five years ago. I still like (and philosophically subscribe to) "I'm waiting for rev B". Though in light of modern expectations of iPad 2, iPad 3, iPhone 5, etc. perhaps today's slogan is "I'm waiting for the next version"...