I burn some pellets in my wood stove to get the fire going good and hot. If you depend on them for all of your heat, they must get kind of expensive. They are about $4 / bag. The bags are 40 lbs. There are 50 bags to the ton.
It's still December and if 6 tons have been burned:
$4 / bag X 50 bags/ ton X 6 tons = $1200
Pellets burn very hot too. 8500 BTUs / lb X 12,000 lbs = 102,000,000 BTUs
102,000,000 BTUs / 92,000 BTUs per gallon of propane = 1109 gallons of propane X $2.5 / gallon = $2772
There's a lot of savings there compared to propane.