LONDON (UK) ADMINS: From NYC to London - Cost of Living (New Yorkers living in London Please reply)?

I do not live in London but my son spent a summer there working on in student exchange. program, He was paid almost double the US minimum wage using the official exchange rates and we assumed that this would be more than enough to cover his expense since he had a very cheap student life style, but it did not. For most things like food both in stores and fast food restaurants ,transportation movies etc it cost a nearly a pound for what you can get here for a dollar, that is 30 to 50 % more, He lived in a dorm so I can not tell you about housing, However health care is free so that saves some money. Part of the reason things cost more is that have a VAT tax of about 20% on everything you buy and part is that fact that they have a minimum wage that is half the median so they do not have the really cheap labor we have in the US .