Last month we wrote about the new Continental OnePass Maximizer where OnePass members could buy double or triple miles in conjunction with a flight. United has an Award Accelerator, US Airways has a Multiplier and American has a Mileage Multiplier option that all operate the same way.

Not surprisingly, Delta SkyMiles has introduced the Delta Award Builder where members can pay cash to earn bonus miles on Delta flights. Pricing is straightforward and members can earn 1,000 bonus miles on a roundtrip flight for $28, 2,000 bonus miles for $56 or 3,000 bonus miles for $84. Miles purchased with the Award Builder are $.028 per mile, which includes taxes and fees. For more information, visit http://insideflyerus.wpengine.com/link/?3195

Bottom line: The cost to buy miles through the Award Builder is exactly the same as what it costs to purchase miles directly from Delta through the Buy Miles program so there is no advantage to buying them in conjunction with a flight. Essentially, it’s just a convenience to be able to purchase miles at the time you purchase your flights–and Delta is hoping that those extra miles will be as tempting as the candy bars are when you’re checking out at your local grocery store. Members wanting to buy miles are better off waiting for a special bonus offer, such as the current 50 percent buy miles bonus that is valid through Nov. 30, 2010. For example, pay $56 and you’ll receive 3,000 bonus miles instead of the 2,000 miles from Award Builder.