If you are buying for immediate burning you would be much better knowing what the moisture content of your wood is rather than the precise volume or mass of it per £.
It's not just a minor technical detail for the geeks, it has a massive effect on the value for money of your heating fuel.
For example, if you paid, £100 for 1 tonne of 50% moisture wood (freshly cut) at 2,200 kWh per tonne net energy output, then 1kWh would cost you 4.5p/kWh
If you paid £100 a tonne for 20% (air dried) moisture wood at 4,000 kWh per tonne then 1kWh would cost you 2.5p. 45% less.
But you wouldnt know which one you had bought. And it's hard to really notice that good wood requires less of it to keep the house warm. But it does. And Ive seen both sold as "seasoned firewood", or "3yr old fire wood" or "barn stored firewood".
I'm just in from my local and had a chat with a good mate who is sells firewood. He's miffed that a guy who promised him 270 tons of oak, felled 30 months ago, isnt honouring an agreement to sell it to him for £55 a ton roadisde. Because that is good wood that he can sell this season for around £100-150 a ton. He could buy wet wood for £40 a ton, but he cant sell it to his customers for 2 or 3 years at least.