We just completed our twice-a-year cross-country relocation. Lots of Interstate Highway travel.
Cheapest gas seen was $2.799 on I-25 just north of Sante Fe, NM.
Cheapest gas purchased was $2.899 on I-70, somewhere in eastern Missouri, I think.
Most expensive gas seen? You guessed it - anywhere in New York was well above $3.50, with Connecticut a close second.
GasBuddy (a worthwhile app if ever there was one) says that all prices have come down in the weeks since we went through the east.
Bill