The Microsoft Store online is now offering a Surface trade-in program that can net you up to $700 towards the purchase of a new Surface. That could just be enough to put a new Surface Pro 4 or Surface Book within reach.

Thanks to Don S. for the tip.

According to the site, potential trade-ins will need to undergo a four-step process: Determine the value of the trade-in, send Microsoft your old Surface, receive a promo code, and then use that promo code at checkout to get the discount.

I’d advise a fifth step, however: Shop around. Other trade-in sites, likeAmazon Trade-In, Gazelle, and others may offer you a better deal.

To see how this might go, I decided to check where my Surface Pro 3 might be worth. The trade-in site asks about a few things—whether it’s working, whether you’re adding the power adapter and a Type Cover, and the storage capacity—and then calculates the value. A mid-level Surface Pro 3 with 256 GB of storage is worth $500. The same device at Gazelle is worth $468, while Amazon was offering more, at $557.

What’s interesting about the Microsoft trade-in deal, however, is that they don’t ask you about the condition (which in the case of this device is probably “good” not “like new” as I really used it): Microsoft just expects it to be acceptable, with no cracks, dead pixels or other obvious blemishes. The other sites do, and you have to do deal with their assessment of the device. Of course, you can also use the other trade values towards non-Surface purchases if you want.

Still, the Microsoft offer looks solid, assuming you’re upgrading. Which, you should consider.