If you live outside London, chances are you have found a cheap source of firewood and pay cash for a farm-trailer load. Pity then the poor city dwellers who are paying at least £120/m3 for their bulk cut firewood; at that price, I'm not sure it offers any cost advantage over gas, oil or electric at all. And the equivalent cost/m3 of those little £5 bags of logs sold at filling stations is about £280/m3
Austria is pretty well covered in trees. Seasoned firewood in 1m lengths is currently about £42/m3; cut into 25cm or 33cm lengths it's more expensive, but there's an even cheaper way to buy it. Call your local ÖBF (Forestry Commission) and they will meet you at a woods near your home and mark a number of trees for you. Cut, split and stack the wood in 1m x 1m piles at the roadside and call the Forest Guy back to pay - this comes out at maybe £21/m3. Of course, you need to season it for two years, but Austrian back yards are like Austrian larders - full of provision.
For all those currently looking to pay £100 a month for their gas, it may be time to get the chainsaw out.
NB for any 'environmentalists' - West Berlin was completely denuded of every last standing tree in 1947 as folk needed fuel. Look at it now; trees regrow. That's the point.