In southwestern Illinois, most prices are around $2.499/gal for regular and have been there for about 2 weeks.
Looking at stlouisgasprices.com, St. Louis City has prices running $2.079 - $2.199 depending on location. Oddly enough, about 2 weeks ago, prices in St. Louis County were lower (by $.05-.15) than in the city but are now ranging from $2.069 - $2.259/gal.