Its about 57 cents an hour, so yes, very expensive if you run it 12 hours per day ($7-8). Upwards of $60 per week to run. Thats $700 a quarter, just on heating.

ETA, DS was born in april, his first winter our power bill was over $800 (ducted- run all night)
After that, we just dressed him warmer.
Wow, that is something we certainly can't afford!! Think I might just leave that heater alone....