With St. Patrick’s Day fast approaching, millions across the UK are getting ready to celebrate on March 17th with plenty of Guinness in hand. But as the festivities approach, one key question comes to mind for those planning their budgets: which UK cities are charging a premium for a pint of Guinness? London is the MOST expensive city for a pint of Guinness this St. Patrick’s Day! To find out, the experts at the price comparison site Idealo have analysed pint prices across a variety of pubs in top UK cities, calculating an average to reveal the cheapest places across the UK to…