mmmm
Assuming the brewing kit and CO2 cylinder is paid for,
£12 for a basic homebrew ale kit plus a bag of sugar(£1?) + say £1 worth of CO2 = £14 for 40 pints - £35p a pint
Made correctly, It'll be waybetter than any canned stuff you can buy for that amount!
If you want to transport homebrew ale it's fine - just make sure you secondary brew it in a pressure barrel rather than individual bottles, and leave it long enough in the barrel to clear and lose the yeastiness. Keep the CO2 topped up once started and decant to a pop bottle just before taking it out - will be OK for a coupledays if kept cool IME.
Coopers Australian Ale is a good reliable budget kit if you like a bitter/light ale type beer.
One good tip I was given is to use half or less the amount of sugar than the kit instructions suggest. Rather than getting 5% type stuff you get a much more quaffable 3.5% - which clears quicker too. We have proven this to be a good tip - 2 barrels side by side -ssame kit different sugar amounts. Everyone pronounced the lower sugar stuff to be a better brew.
Imperial Dave may be able to tell us why?!