I "buy" points paying federal and state income tax, usually at half price by using the Amex Starwood card for the 5k bonus and the Chase United card to reach the 25k minimum in order to get the 10k annual bonus. The new rate for Federal payments of 1.88% or 1.89% for Amex combined with my tax deduction bracket for the fee effectively puts my cost at under 1.1 cents per mile for the United Visa miles and slightly more for the Starwood points when used for the 5k bonus on airline miles transfers.