its $3.16 at the thornton's gas station by my house, the last time i checked. the price changes every single day. but in the city i have seen it as high as $3.30 a gallon.
try this site to find out cheap gas by you
GasBuddy.com - Find Low Gas Prices in the USA and Canada
but i dont understand why you need to use a 93 for your car. any gas will do, as long as you use the the same kind of gas.