Originally Posted by
Worcester
I would be curios to know where you got those figures on water from? Given the
cost of a plastic bottle is around 2.5p and that as I recall you can but 0.75L bottles of water at WHSmith in T5 for £1.50 that seems to exclude the possibility of such high mark ups.
...
I think you are confusing a percentage mark-up with a price-multiple.
A mark-up of 100% would be a price of 2x the actual cost (C), or numerically, price of C + {100*C/100} = 2C. Similarly a mark-up of 300% would be price of C+{300*C/100} = 4C.
Following that pattern a mark-up of 2000% equates to a price of 21C.
Assuming just the bottle cost of 2.5p that gives 21*2.5 = 52p. The price of 1.50GBP would be consistent then with a 2000% mark up if the water in the bottle has a value of around 5p, which doesn't seem too far off given that the price of tap-water is less than 1p per litre.