Mate, never buy anything it a Bricks and Mortar store until yuo have done an online price check. The easiest way is to just goole an item, but instead of hitting 'Search' hit 'Shopping' and it will bring up the cheapest online price.

Amazon will almost always be cheapest as they have a very sophisticated pricing robot that matches/slightly undercuts the best online price

P.S Take it back, get a refund and buy it from Amazon