When Microsoft unveiled the Surface Pro 3, they made a huge point of how it compared to the MacBook Air. Now Microsoft is firing shots at Apple’s laptop again offering customers up to $650 to trade in their MacBook Air for a Surface Pro 3. Assuming you get the full $650 credit, you can get a base model Surface Pro 3 for only $150. The deal lasts until July 31st, but you’ll need to find a Microsoft retail store. Learn more about the deal at Microsoft’s website.