Originally Posted by
beaubo
I have always been a proponent of valuations based on actual cost of miles earned versus trying to figure out if miles are a good value compared to a 'retail' fare.
That is valid for the true mileage whore.
I would go with your method, but only include the marginal spend that was done specifically to earn miles.
For example, I'm going to Australia on Saturday. I'll get around 20000 miles in my AC account for the round trip. But I would have gone anyway, probably on the same airplanes, so it's not like I (rather, my employer) really spent anything to get the miles. They were just given to me.
Sometimes I'll buy up to get a miles earning fare, or buy a more expensive *A ticket to consolidate miles. So sometimes there is a marginal cost for miles, over and above the actual travel.