$39 to $289? Yes. And less when you factor in check-in and other costs (remember three checked bags free when you fly First Class with Delta).
Delta's low domestic upgrade surcharges—surprisingly low, see chart below—will have you scratching your head.
Or shaking it... if you have elite status with that airline.
Why use Delta miles to buy a Delta domestic upgrade when moolah itself is so much cheaper, and easier?
Details in this month's cover story, Master Delta's Six-Tier Upgrade Scheme for Domestic First Class and Upgrade for Peanuts.
All the nuances you need to know.
The article includes a chart with the economy fare codes to look for. (Good news: there's only one that doesn't allow it, unlike the five that don't allow loyal program members to upgrade with miles.)
There's this chart too; check those (pleasantly) surprising surcharges:
