The MacBook Air is a very capable laptop, so much so that its success pretty much ushered the era of Ultrabooks all by itself. “Capable laptop” however doesn’t stop companies like Microsoft from competing, and the boys from Redmond are pushing the Surface Pro 3 pretty hard. To reach their target demo, the company is running a promotion until July 31st where you can get up to $650 if you trade in a used Macbook Air. That amount then has to be put towards the purchase of a Surface Pro 3. Considering the laptop/tablet hybrid starts at $799, you’ll have relatively little money left to pay. Whether or not you consider this a good deal probably depends on the amount of cynicism you harbour towards Microsoft’s products. But if you’ve got an MBA just lying around, now’s a good time to get something for it.