You leave out some important considerations in your assessment concerning wood vs proppain. One thing, not everyone has access to a woodlot, Obviously you do but you need to factor in some things like what is your time worth? Takes time to cut, split, stack and handle wood plus the cost of the woodburner, the gas for the chainsaw, the chainsaw itself and then the consumables like chain loops and bar oil, lets not forget safety gear like chaps and a helmet...and gloves and an axe and splitting maul or better yet, a gas powered splitter,a dnt e gas for the splitter... I could go on.
Bottom line is, it all costs money for the 'free wood' thats really not such a good deal anyway.
Propain, on the other hand is one time cost. It's a good deal. I have the wood too. Most of my wood from my acres of trees, I chip in my big chipper or burn in a pile. I tried giving it away, but no one wants to spend the time to haul and split and stack it so I roast it yearly. Makes a helluva bonfire.