If you burn wood check at small sawmills in your area to see if they cut railroad ties. At least locally, those who do will let the cut off ends be hauled off free. They are either oak or popular and usually about 6" x 8" and from about 8" to 20" in length. They split fairly well by hand and work very work very well on a hydraulic splitter due to a flat bottom. The larger ones would be 'all nighters'.
When I first read the subject line, I was thinking creocote (sp?) ties. Wouldn't that be a good fire. When I was growing up in MT a neighbor worked for Burlington Northern, he would bring broken and old ties home and cut them up for his wood stove. He said they burned hot and a long time, but their clothes always smelled like creocote.
We would sometimes go the log home builders and pick up the end of the logs for $10.00 a pickup load. It didn't matter if you had a pickup with sideboards or not, price was still the same. A lot cheaper than cutting your own.