My folks are considering a purchase of a treadmill for their use at home and the only factor seems to be how much of a dent is this going to put on their electric bill. I've never used one at home (I go to the gym or run outside). Does anyone here have one at home and noticed how big of an increase their bill was (figure an hour's usage per day)? Their reasoning is if its going to cost more than a gym membership, they'd rather do that than buy a treadmill themselves.