Looking for a gift that will top off your mileage account as well? When you purchase SkyMiles between now and Dec. 31, 2007, you will receive 20 percent more miles. Buy 10,000 miles and you will receive an additional 2,000 miles, which you can give to the recipient or keep for yourself. You must purchase at least 1,000 miles and miles cost $0.0275 per mile plus a 7.5 tax. You may only purchase a total of 30,000 miles per calendar year.