In 2026, the cost to purchase air miles directly from an airline typically ranges between 2.5 and 3.5 cents per mile. For example, if you wanted to buy 10,000 miles to top off an account for a reward flight, you might pay anywhere from $250 to $350. Airlines like American, Delta, and United often sell miles in increments of 1,000, and they frequently run "bonus" promotions where you can get 50% to 100% more miles for the same price, bringing the effective cost down to around 1.5 to 1.8 cents per mile. However, it is important to note that the "real world" value of a mile when redeemed is often only 1.1 to 1.4 cents, meaning that buying miles at full price is usually a bad investment unless you only need a small amount to reach a specific high-value redemption, such as a First Class international suite. Always calculate the "cents per mile" value of your intended flight before clicking buy, and remember that many airlines also charge a processing fee or tax on top of the listed price for the miles.