Question: are delta mileage boosters worth it?
Answer: Delta's Mileage Booster offers somewhat better value, but it's still not great. You can buy miles for just less than 2 cents apiece when you select the largest booster package (3,000 miles for $59); that's well above my valuation of 1.2 cents apiece. ... Buying extra miles at check-in isn't a good deal.