Is the "online price" from WalMart, or is it from a third party vendor?
I just looked, and for me it is $27.31 online, and the vendor appears to be WalMart. I'm just one state over from you.
Also noticed WalMart shows 10w30 T4 Ultra, for $19.39 a gallon.
I've had better luck with getting Rotella at a good price at Rural King or Menards. Not sure if either is a possibility with you.