Re: One problem with this
" Give it time, and a £50 note will buy just one Mars bar [...]"
In my 1950s childhood a Mars bar was a rare treat dispensed by a spoiled cousin. He also had a collection of expensive toys including Britain's model field guns with spring-loaded shell casings. Anyway - a Mars bar then cost 6d - (2.5p). Nowadays they are probably smaller and cost in the order of twenty times the nominal price.