Cost to heat varies between areas, type of heat, desired temperature, etc. For us, we like the toasty warm living area that would cost a fortune if we kept that temperature with our oil furnace. We also need to keep the house warm all day, every day, because we have a licensed family daycare, so no turning down the heat during workdays.
$7000 seems like an awful lot to me for a pellet stove though. I started years ago with an Englander stove from Lowes that I installed myself and used for 11 years. Then a couple years ago, I upgraded to a lightly used Harman that I picked up for $2000 and installed that one in place of the Englander. Last year I burnt about 4 1/2 tons of pellets, but only use barely a quarte tank of heating oil. If I kept the house as comfortable with the furnace, I would have used multiple tanks of oil at about double the cost.
For electricity, I tested my stoves wattage use because I put in a battery backup for short outages or to give me time to use the generator and it uses very little while it's up and running. it was below 100 watts for the fans on lower settings and jumps up some for the auger cycles. My UPS gives me about an hour if power goes out.
We run the stove 24/7 and my winter electric bills averaged around $120
Ray