I would look elsewhere for an electrical problem...A/C, hair dryers, clothes washers/dryers, fans running 24/7 because of the heat? even if your chest freezer ran 5 hours a day that wouldn't cost an extra 80 bones, unless your paying .75 per Kwh or more. Perhaps a pool pump running more? Its summer all your fridges are running more!
Electrical draws can be found (or at least the start of locating them) by looking at your meter and having someone turn off 1 breaker at a time untill you find the 1 that is spinning your meter real fast. Make sure all compressors (A/C, and all fridges/freezers) are on at the time of testing.
Sounds odd to have an $80 jump from month to month. Did your rates go up? Call your city..