The war is starting to hit food stuffs in the UK. Bear with me here there are lots of figures flying around. So 70 shillings is £3.50 and the cwt weight unit is the long hundredweight (cwt), not to be confused with the short hundredweight used in America. According to Wikipedia 1 British cwt is 50.802345 kg.

Jan13 1915 Cheese prices rise, Canadian cheese from 70s to 82s a cwt (£3.50 to £4.10 for 51kg) http://t.co/KY6TtGhORh pic.twitter.com/cZB2Hj0zbJ — WWI covered live (@ThisDayInWWI) January 14, 2015

So before the war Canadian cheese was £3.50 for about 51kg. Adjusted for inflation that is £245 in 2015. Looking at UK supermarket Tesco in January of 2015 Canadian cheddar cheese sells for £12.50/kg so in 2015 1 cwt (51kg) would sell for £637.50 or about three times what it cost back in 1915.

If you like this price analysis check out my run down of what it costs to outfit a British officer here.