Just a few more quick back of the envelopes if anyone is curious.
In my area (the Socialist Republic of Canadastan), a load of logs is generally $950 for about 9 cords, nat gas is 50 cents a cu meter, fuel oil is $1.09 per litre, electricity is 20 cents per KwH. These prices take all factors like delivery costs and services charges into account. We will use RSI's number for propane at $1.59 per gal. If we convert everything to BTU's and then figure out how many BTU's we get for a penny and then factor in the efficiency of the furnaces (very subjective of course) we get a useable output cost.....
wood 2278 BTU/cent @50% eff = 1136 BTU/cent
nat gas 714 BTU/cent @95% eff= 678 BTU/cent
propane 588 BTU/cent @95% eff= 558 BTU/cent
oil 333 BTU/cent @82% eff= 273 BTU/cent
electricity 170 BTU/cent @100% eff= 170 BTU/cent
Using wood as the baseline
wood 1.0x more expensive than wood
nat gas 1.7x more expensive than wood
propane 2.0x more expensive than wood
oil 4.0x more expensive than wood
electricity 6.7x more expensive than wood
Of course, many here get their wood for free, but this usually entails more work. Some may have wood lots and like to keep the dead stuff cleaned up, so wood is the best choice for many reasons. For me, if the option is oil or electricity, I would go with wood for sure. If nat gas or propane is available, then you had better not hate handling wood, as it is a tougher case to make.