have you been in a bar waiting to be served behind someone waiting for a couple of cocktails?
Adding lemonade to a pint glass before pouring in half a pint of lager isn't going to break their serving timings..
But it's quicker to make a shandy than to do a half a lager and half a lemonade. By that reasoning a shandy should be cheaper than two halves. (which it isn't)
Getting charged the cost of a pint of lager for a lager shandy, it’s half lemonade should really only get charged for a fucking half of beer.