While it seems from this offer is that you can just purchase an upgrade for those amounts below, the "upgrade" price is actually loaded into the fare results so you can just select first class at the time of booking, which takes the hassle out of trying to apply an upgrade after the fact and hoping for availability.
Lately, I've purchased several discounted first class fares from NY to Florida since they earn 150% class-of-service bonus, and it's nice not having to fight for a Medallion upgrade - which become even scarcer when Delta sells all these discounted first class seats. One of the major trends I see in 2013 is for airlines to further monetize their first class cabins (I heard this loud and clear at United the other week) and I bet Delta is going to make it easier than ever for people to purchase up into domestic first class (right now you need to purchase a mid-tier K fare or higher).
From the sample list above, I searched ATL-JAX, and the price difference is indeed only $39 more for first class. When you factor in that you would be allowed 3 free checked bags, a 150% class of service bonus, Sky Priority access, and a first class seat so you wouldn't have to fight for a Medallion upgrade, it seems like a good deal.
After a few cursory searches on Delta, it seems most of the routes where these discounted first class fares are available are short- and mid-hauls, rather than any of the transcontinental routes they're likely to come in handy for me. But if you're still thinking about some holiday travel within North America, you could score an upgrade without shelling out too much more money, and it's a great way to get some bonus Delta miles in the process as well if you're gunning for elite status and still have a ways to go.
From the Terms & Conditions:
Restrictions | Fares shown are available at delta.com. Tickets cost $25 more if purchased from Delta over the phone, $35 more at a Delta ticket counter or ticket office, and these amounts are nonrefundable. Tickets are non-transferable. Seats are limited.
Tickets | Tickets may be purchased any time prior to the end of the applicable travel period for travel to/from anywhere in the contiguous US 48 states and Canada.
Travel Period | Travel may be on or after December 15, 2012 and must be completed by January 5, 2013.
Blackout Dates | No blackout dates .
Fare Validity | Fares shown are valid all days of the week based on availability. Fares are valid in the first class cabin on nonstop Delta/Delta Connection carrier flights only.
Minimum Stay | None
Maximimum Stay | None
Cancellations Refunds | Tickets are nonrefundable except in accordance with Delta's cancellation policy. Fees may apply for downgrades/reissues and itinerary changes. Contact a Delta agent or see Ticket Changes for details.
Baggage Charges | First class baggage rules apply. Allowances subject to size/weight limits. Contact a Delta agent or see Checked Baggage for details.
SkyMiles Partner Offers | SkyMiles partner offers subject to the terms and conditions of each individual offer. SkyMiles partners subject to change. All SkyMiles program rules apply. To review the rules, see Membership Guide & Program Rules.
Miscellaneous | Fares, fees, rules, and offers are subject to change without notice. Other restrictions may apply.
