As cat litter, the local price per bag was about 2X the fuel cost price.
I run a pellet stove, it functions much like a blacksmith's forge with 3 electric motors.
The fire is about 6" wide and 3" from front to back. That's it to heat 2 x 1200 sq ft.
Delivered to my front yard as 50 x 40lb bags, triple wrapped in plastic on a pallet,
I pay $235/ton. Average 5 tons per winter. At -20C, that's close to 3 bags per day.
What I can tell you as an industrial fact is that the pellets are not air dry, they are oven dry.
Just sitting, bone dry in my lower kitchen from April to the next October, they do not burn efficiently at all.
They can suck up ambient humidity and that's unstoppable.
Of course, I have a complete, oil-fired central heating system in the house for when I'm away.
The pellet stove runs out shuts off, cools down and the oil furnace takes over.
This winter, from December 27th, I was away for 63 days.