You can do this one all sorts of ways with a HT from TFD. You can do the lowest CPM weekdays in coach but look at weekends too for same price but higher CPM. Lastly the 1st class price is not all bad. Here are the lowest numbers:
5,534 MQMs at 3.6 CPM
Bookable on Delta.com
DM yields a nice 12,452 Skymiles per CWSI.net!
Bookable starting in SEPT and to year end. A sweet deal for you west coast folks or worth a position flight too!