First of all, credit limit $3000 is for the total amount you can borrow from the card, not for each month.Maybe it is typo, you mean $30000. Second, after you get the huge amount of credit debt, say 27000, it will be very hard that you can get 0%apr card any more, since your fico score is directly related to the debt/credit ratio. Other than that, I think it works as you said.