I just got back from a trip to Illinois. The lowest price I paid for the 10% ethanol blend was $2.70/gallon. That was in Platte City, MO north of Kansas City. The lowest price I noticed along I-70 was $2.75/gallon. I think that was around Oak Grove, MO. It's about a fourth of the way from KC to Columbia.
It seems to be costing about $2.90/gallon in southeast/south central Nebraska.