What's cheaper, an hour of toaster oven power or an hour of oven gas?

I have one of those 10 year old toaster ovens that works awesome, simple, heats up quick, and draws so many amps you see the lights dim when it kicks on. You could almost swear that little maniac machine is vibrating as it heats your stuff up. Do you think it's cheaper to run that for an hour and pay the power, or pay for the power of heating up an oven for an hour? In this case I'm cooking a TV dinner that takes an hour (no microwave).