My first trip to England I was exposed to the 'old' system. Being young and alert and mathematical, I found it not only quaint but a lot of fun. Explained a lot of the references from Dickens and Conan Doyle and The Goons.
The very next year they'd shifted to the New Pence and the decimal system and a lot of the small prices hadn't changed, I don't remember specifically which ones, but possibly tube entrance was the same number New Pence as it had been Old. Which meant a 140% boost in real value.