Anyone have experience with Heat Surge heaters? Do they increase the electric costs substantially?

Gas bill is skyrocketing this cold winter. I'd like keep one room of a small apartment warmer than the rest of the house, to save on the gas bill, but if it runs up the electric bill as much or more, why bother, so I'd like to know the real story. They claim it costs only pennies a day to operate, sure that might be true, but is it a hell of a lot of pennies?