Wine is expensive in the UK because of alcohol duty and tax - the value of the wine in a £5 bottle is 47p. Lots of alternative cheap sources for wine in the New World. 

There is no VAT on food in the UK as in the rest of the EU and food from outside the EU will not be subject to the tariffs now in place to protect inefficient French farmers.

There weren't restrictions on travel before the EU - except for the countries that were behind the Iron Curtain.. Passports were needed, and still are now, to enter a Schengen country as there is no national ID in the UK.. Any person can travel freely within Schengen - even Canadians ;-)