Originally Posted by
polychro
Have you considered mileage plusX? I accumulate redeemable miles much faster than flying. Example: recent $355 Legal seafoods bill (large family) gave me 355x5 plus 25% + 355 = 2574 miles (25% bonus if mileage plus branded credit card used). Miles are credited instantly. Compare with a recent flight EWR-GVA, 3850 miles on a cheap ticket gave me 1890 miles, and that is for platinum elite.
MileagePlus X is great, but it's not going to be cheaper than buying miles outright. It may be a better value, if you use it for things that you were going to buy anyway, but if you're purely looking at the costs of acquiring the miles, it's not competitive with Award Accelerator.