Best Buy just sent us through a very interesting email. For the next week it will be offering a $25 gift card with any iPhone 5 purchase with a 2-year plan. We’ve already heard earlier in the week regarding RadioShack, who are currently offering $20 off the upfront cost of the iPhone 5, as well as $50 off the iPhone 4S. It’s fair to say that the Christmas retail battle is heating up nicely.