Costing a mere £2.30 for a ticket which enables you to use any Travel Coventry bus from the first of the day to the last, simply get the 20 bus from the Burges in Town and get off by the Tesco's on the Foleshill Road.
A very regular service runs on match days and the journey time is around fifteen minutes.
Easting and drinking in the various establishments in Coventry City centre may also save you money compared to the prices charged by the catering company in charge of the Arena.