It really depends what you're going to do with the miles. If you spend 25,000 miles for a $200 ticket to go cross country (and had to make $25,000 in purchases to acrrue those 25,000 miles), they're worth less than a cent each. If you spend 90,000 miles to go to Australia in business class, which would be a $6,000 ticket, they're worth a lot more. There is no single answer that applies to everyone. It comes down to what you're going to use the miles for.