Good idea, elvis, but the way to avoid the almost certain rising cost of wood is to get your wood for free. We know some people who own a wood, so we can luckily get our wood for free. I do realise that not everyone is so fortunate, but you can strike lucky if you ask to empty out skips of wood which you see on building sites. I have done this a few times (with full permission of course) and have been told that I am doing them a favour by taking it all away as they do not have to have the skip emptied so often. You often see broken pallets in them.
The downside of this is that you have to break up the wood yourself, and then transport it. You know what they say about wood. It keeps you warm twice, once when you cut it, and again when you burn it.
Don't know where to get free gas and oil from though..sorry.