I have because we don't have gas. My son has gas and it seems more expensive. But it's difficult for me to say really because I can't compare to anybody with a similar property.
Not much between them I think.
Cheapest at the moment per btu would be woodchip .. especially since new Government kickback scheme announced in past week.
Cheapest btu per pound has got to be woodchip.
My daughter lives in a village, with no gas and was having central heating installed in her house. She investigated different systems and was informed that liquid gas had roughly half the running costs of oil, so that is what she had put in after having the tank fitted in the garden.