Question
When buying a seat using miles, I miss out on so much that has value to me as a frequent flyer:
*Miles from the credit card purchase, plus bonus miles from being linked to that airline
*Miles from the flight, plus bonus based on elite status, plus bonus based on class of flight
*Miles from the flight toward elite-status qualification, plus bonus on class of flight purchased
And the airlines don't let seats go cheaply, in comparison to how much flying it takes to earn those miles. So how do you weigh all the factors that need to be considered when deciding whether to buy a seat using miles or money?
-- Sitting Tight

Answer
We’re lucky to be able to feature some advice from FlyerTalk member, Pizzaman, who personally wrestles with this question whenever he considers any award redemption. But before moving on to Pizzaman’s answer, there may be another answer to your question -- and that is to merely forget all the metrics of award redemption and treat it simply as you would the pennies and nickels you might have saved in the piggy bank. Who really cares if it’s the right value? The fact is that most members of frequent flyer programs use miles for redemption of aspirational trips.

For instance, many years ago I used a substantial number of frequent flyer miles to fly my father, sister and her husband to Hawaii in business/first class so that my father could revisit the locations in Hawaii he remembered from his deployment back in World War II. The value to my father and the satisfaction I personally gained from such an award redemption surely could not be calculated in any buy vs. save theory. Fact is, I really did not have much money at the time and my father was getting along in age. At that moment, it really did not matter what the actual financial value of the redemption was, but only the aspirational value, and that’s often overlooked. I’m all for making sure that you think things through financially when using your miles, but I also see these as “rainy day” miles, meaning that they are earned without any specific need in mind. So while you and many others absolutely should have some basic considerations in mind as to whether to buy a seat with miles or money, it’s also OK to let that fly out the door when it comes to a very high-value aspirational award redemption decision. But now, I’ll let Pizzaman have his say.

Advice from Pizzaman:
There are two schools of thought here. One way to go is to burn miles when you have enough for the award you need. The other is to look for the best value. Both have their merits.

Since most airlines devalue their miles over time (by increasing how many miles it takes to redeem an award), there’s a big camp of people who believe you should burn miles as soon as you can to avoid these devaluations. Most of the FlyerTalk members in this camp still believe you should get reasonable value for your miles, but don’t believe in a long-term “hold” strategy.

The other theory I mentioned is to save the miles until you can “earn” a good value for them. What’s good? It depends on your financial situation. If you have enough money to buy the ticket without using miles, then I’d hold out for more value. Personally, if I can get 2 CPM (cents per mile), I’m all for it. If my redemption rate is less than that, I will usually hold my miles for another time. When you consider international travel, it always seems like I can find a really good value when I need to.

As always, your mileage may vary (literally)! My advice would be to hunt for those great values. There’s enough of them out there.