Out of interest, for the first 7 AGs, I calculated the exact cost per pint, using proportions of malt & hops used, plus yeast (dry pack). I didn't bother to factor in the likes of Irish moss, CO2, water, water treatment, sanitiser, electricity, etc. And I more or less followed clones of well known beers, not particularly high ABV or hoppy. Cheapest was a 4.7% with 67g hops (fuggles), @ 22p per pint. Most expensive, @ 32p per pint, was shared between 2 brews. First was 4.3% and 85g hops, second was 8.7% with 62g hops. The range of the 7 gave me a feeling for the general cost. I should mention that I was sourcing malt at about 85p per kilo, so pretty cheap.
One of the 32p per pint was a clone that costs 1.70 pounds for 33cl in the supermarket. So that's roughly 120 pounds worth of beer for about 13 pounds.
For the mentioned none factored in costs, most of the stuff is negligible when divided by 40 pints, but CO2 for cornies is not so cheap. I estimate about 5p per pint (on top of the earlier mentioned costs). So I decided I'm switching up to a 10kg bottle, as the cost of CO2 is almost the same for 5kg as it is for 10kg. Just got to swallow a one off charge for upping the bottle size.