As I said before, the efficiency in firewood comes from selling it green.
Cordwood - £52 a tonne delivered in. That's allowing a tenner a tonne for haulage.
Let's assume it's a hardwood mix, with some heavy species and some not so heavy. So perhaps 2.2 cubic metres to the tonne. Raw material cost is £23.64 per cube.
Let's also assume there is a decent processor involved. Hardwood is slower than softwood though (which I am reliably informed takes around 7 minutes per cube on average) so lets assume 20 minutes. Assuming you've got two guys on £8 an hour operating and supplying the processor, you've got a labour cost of £5.28.
Assuming your processor is diesel and it's doing 25 cube a day, it (and the forklift) might use about £1.50 in diesel per cube.
So you've got a produced cost (in yard, not delivered) of £30.42 per cube.
Yard costs - my yard (in it's original, and smallest incarnation before I expanded) was about a third of an acre (with a couple of small barns) and was large enough to accommodate 3-400 tonnes (800 cube) of firewood a year. That part of my yard costs me £330 a month, plus VAT. So £3960 a year, which is £4.95 a cube.
Delivery vehicle costs - Assume you buy a new 12ft Ifor tipper and a used £10k landy. Total cost £15k, value after 3 years probably £10k. £5k depreciation, plus probably £5k repairs is £4.16 a cube.
Machine costs - processor £15k, forklift £3.5k, chainsaws and other tools £2k. Again, assume a 3 year use and that it can be sold at the end for about £15k total. £5k depreciation and £5k repairs/maintenance is again £4.16 a cube.
So that's a fully costed in yard product at £43.69. The only other cost is the diesel to deliver it and the time of the person running the delivery. Given that a cube can be produced in 20 minutes (and is costed from the point of view of hired in labour), I struggle to figure out how just over forty quid becomes £120.