i havent seen it change much, slight drop of a few pennies.
its not $2.21 for 93 octane (that is with 6 cents off on fri) or 2.27 normally. I have seen 93 as high as $2.37 around here.
gotta love NJ's low gas prices and full service
but yea i have always put 93 in my car. dont know why...