How many is 4 sets? I work at a sign shop, and we normally sell sets of 1000 business cards for around $35 or so. It may be worth your time to let someone like me do it, get a great quality card, and not have to purchase ink and card stock, and probably still save money.
EDIT: Forgot to say that the price is obviously dependant on colors and the type of card used, but the quasi-$35 price is typically for a good card stock and 1-2 colors.