Right now natural gas is cheaper, if you have it. If gas were to be brought up my road, I'd tie in tomorrow. I'd keep my boiler, but I'd be putting in a natural gas burner! Then I'd slowly start stockpiling coal for when the price goes up. Nice to have flexibility. Seeing I don't have gas, I'm saving 65-70% over what I'd be spending in oil, and more off of propane.