Burger King is letting you decide how you want its 2-for-$5 promo. For a limited time, mix and match two sandwiches for $5. Choose from the new Extra Long Cheeseburger, Original Chicken Sandwich, Big Fish and Big King. You must purchase two to get the discount. (If not, expect to pay full price. With some of the sandwiches costing around $4 at regular price, why not buy two?) At the discounted price, if you’re really hungry, you might be able to eat two — just skip the fries and soda. Or, better yet, treat a friend. The lineup changes every few months, so check the menu first for the special before ordering.