Electric furnaces use on average about 20,000 watts. Current RI rates w/all fees is about 31c per kilowatt hour. So for every 1,000 watts used per hour, you pay 31c. With your furnace, that's $6.20 for every full hour it is running. That can add up quickly.

PS5 uses about 200w (so about 6c/hr). Nothing to be concerned with.