Most of the things mentioned you can do cheaper. For example, if you need a prescription for two items, you can pay £10 a month for a prepay card which covers as many prescriptions as you need.
Branded dishwasher tablets are expensive which is why I don't understand why people buy them when aldi and lidl version are just as good for a quarter of the price.
Most airports have water fountains, just take your own refillable bottle and consult wateratairports.com
Coffee from Greggs or McDonald's is half the price of the coffee chains and just as good.
But I agree that spirits, cocktails and wine in pubs and bars is ridiculously priced which is why I generally stick to lager, which works out cheaper.