If you’re on the fence about Microsoft’s excellent Surface Pro 3, the Redmond company is hoping a little promotion will help make your decision a tad easier. Microsoft on Monday opened up a new trade-in offer that will give MacBook Air owners $650 if they purchase a new Surface Pro 3. The cheapest Pro 3 will start at $799—that’s the Core i3 version. Unfortunately, it won’t actually be out until Aug. 1 (same goes for the i7 version), so you’ll only be able to purchase the i5 version, which starts at $999.

The deal is only valid in Microsoft retail stores in North America, so you won’t be able to take advantage online. Below is some of the small print straight from Microsoft.

Device must power on to be considered working. Water-damaged devices and devices with cracked screens are not considered working devices for purposes of this offer. Trade-in value may vary. Condition, documentation and accessories may affect value. Microsoft reserves the right to refuse any trade-in or limit quantities for any reason. Requires purchase of the Surface Pro 3 to get the maximum trade-in amount

Obviously your trade-in value will be determined by how new your MacBook Air is, but it doesn’t appear Microsoft has set a cut-off for how old Apple’s computer can be. If that changes we’ll be sure to update this post. Microsoft says that before trading your device(s) in, you’ll be responsible for removing any data, meaning you have to wipe your machine before going into the company’s store. Microsoft has set a limit of one per trade-in/purchase, so you can’t go in trading two MacBook Airs for one Surface Pro 3.

The offer is valid through July 31, so you have plenty of time to make a decision. Let’s be honest: $650 is quite a bit, but you’ll likely only get that amount for a newer MacBook Air in pristine condition. That said, if you’re really intent on trading up to Microsoft’s laptop/tablet hybrid, this is probably your best chance to do so.

But is it such a good idea? Apple has Yosemite coming out this fall for free, bringing with it a ton of great continuity features (that is if you also own other Apple gadgets). Also remember that you don’t get a Type Cover with the Surface Pro 3, which is $129 all by itself. So, at minimum, you’re probably going to spend about $1,129, and that doesn’t include tax. Still, you’ll be (potentially) getting $650 off the purchase price, which is quite a bit, and makes jumping into Microsoft’s crazy hybrid future a lot less expensive.