You have decided to take your daughter skiing in Utah. The best price you have been able to find for a roundtrip air ticket is $545. You notice that you have 20,000 frequent flier miles that are about to expire, but you need 25,000 miles to get her a free ticket. The airline offers to sell you 5,000 additional miles for $0.06 per mile
Suppose that if you don't use the miles for your daughter's ticket they will become worthless. What should you do?