Refurbished 5D mark iii is out of stock the most of the time. At least I couldn't catch one in stock.
Looking at canonpricewatch.com how do I know if camera has full USA warranty?
Because canonpricewatch says it is. They have a sort of pool of authorized dealers who are willing to discount, but they can't advertise the price for fear of the wrath of canon. Just fill out the form and you'll get an offer from an authorized seller for the low price with full USA warranty.