The cost of firewood is mostly in the labor of cutting, hauling, stacking and tending the stove. You either pay someone to perform some of that labor or do it yourself. The amount of labor per cord required is always the same. It’s a lot of work. Or a lot of money depending on how much labor you are buying. With petroleum products you are at the mercy of your supplier. Price fluctuates wildly. I prefer to cut my own four cords of wood per year myself. It’s always a lot of work but it doesn’t change. The only thing that changes is my ability to do the work. Tough getting old. This year I bought half my wood. Supposedly burning wood is carbon neutral. You cut the tree, a new tree grows back. Now I don’t have to feel guilty about not freezing to death.