American Airlines and US Airways are merging, so their loyalty programs will eventually be merged and can already be used to book award travel on each others’ flights. It is very likely that miles in the two programs will be combined at a rate of 1-to-1 (one US Airways mile becomes one mile in the new American Airlines), though we don’t know what the new award chart will look like (probably similar to American Airlines’ for at least a short honeymoon period).
So now might be a good opportunity to buy miles in one program or the other if you need to use them for travel on the other carrier, can’t buy enough miles with only one program, or want to speculate on the value of those miles increasing as the merger progresses. But in general, I only encourage people to buy miles when they have definite travel plans in mind.
Buy US Airways Miles for 1.88 Cents Each
US Airways is currently offering a special 100% bonus promotion on purchased miles through January 31. This is only available to people who bought miles at some point during 2013. I don’t recall getting an email, but when I visited the link shared by Loyalty Traveler and input my Dividend Miles number, I was provided access to the bonus offer and thanked for my past purchase.
Because it is a simple 100% bonus on any purchase amount (up to 50,000 miles, for a total of 100,000 miles after the bonus), you pay pretty much the same price for however many miles you need. It would cost $1,881.25 to receive 100,000 miles.
One of the best ways to use US Airways miles is to book travel on Star Alliance partners while it remains in the alliance. For example, travel from North America to North Asia (e.g., Japan) is only 90,000 miles round-trip in business class. Include a connection in Europe along the way and you might still be able to get the same price depending on the agent (or it will be priced at 100,000 miles, which is the more expensive of the two destinations).
View from the Wing has a good guide to using US Airways miles, and I’ve updated the US Airways award charts on my Resources tab. US Airways has less flexible award routing rules than United Airlines, but at least their award chart is definitely cheaper for certain routes if you aren’t interested in the complicated stuff. These miles are also the cheapest to acquire for booking awards on American Airlines.
However, booking award travel on American Airlines means you must use AA flights only and cannot include other AA partners. I ran into this problem recently when booking an award that included flights operated by American and Alaska Airlines, so I had to buy some American miles instead.
Buy American Airlines Miles for 2.28 Cents Each
Fortunately American Airlines is also offering a promotion through January 31. The price isn’t as cheap but still not bad to top off your account for an award — exactly what I did. This time the price does get better the more miles you buy, up to a point. The best value is in purchasing 45,000 miles and receiving 15,000 bonus miles for a total price of $1,365.31 (including taxes and the $35 transaction fee). The average cost per mile is 2.28 cents.
You can buy more miles, up to 60,000, but the bonus will still be only 15,000 miles for a total of 75,000. Since the bonus doesn’t change, you end up paying more per mile on average when you include the bonus miles.
UPDATE: As Joey suggests in the comments, those who want to purchase 60,000 mile should do so in two transactions: 45,000 + 15,000 bonus and 15,000 + 4,000 bonus. The total miles received will be 79,000 miles (instead of only 75,000 miles) and the total cost will be $1843.75 including taxes and fees. The average cost is 2.33 CPM vs. 2.41 CPM if you buy them all in one go.
The disclaimer warns that you may not receive the purchased miles for a couple of days and that the bonus miles may take five days to post. In my experience, I received all the miles within 24 hours even though I purchased them over the weekend. However, keep this warning in mind. American Airlines lets you place award travel on hold for five days without ticketing. Even if it does take five days for the bonus miles to post, you will have enough time to purchase and receive the miles to go back and issue the award.