Why limit yourself to DL? Are the GM perks really worth THAT much??
If you take non-stop with US from TPA to PHX (depart Dec 31) you pay under $500 and CO is under $400.
In times like that, I gladly forgo my preferred airline and do what is reasonable, logical and right. Some people are so blinded by frequent flyer programs that I sometimes understand why Chris Elliott writes what he does about such programs!