I get how "your" firewood is cheaper than LP, but let's now look at it from the ground up with no freebies.
Required items: Buy raw logs +/- $300 a load, now buy saw +/-$500. now buy splitter +/-$2500. Buy fuel/oils $3.50/gal. get 2 cords of split wood, now wait the year or 2 for it to dry, meanwhile heating your house with LP. Then the following year you have wood ready to go, but now you have to make more, buy another load of raw logs and start over. A few years in you Buy land that has trees, +/-$40k (just to give it a value). oh but wait there's more, now you need a way to get the logs up to the splitter so your need a tractor or a 4-wheeler +/-$4k, it takes at least an hour for 2 people to split a cord with your now 4 year old splitter. Now onto manpower: how much do you like to get paid an hour, even at minimum wage that's another $30/hr tacked on per cord. to increase output you're now buying a processor @ +/- $15k, all so you can have a little wood heat... And none of us would trade it for anything, especially to not see that fuel truck backing in the driveway!!!
Ok this was all in fun and no actual Math was used in the making of this story!!