there is no buyback or trade in policy.
The closest thing to it is if your Nook is broken and out of warranty you might get a discount, but generally it isn't on one of the newer devices.
It's about the same as if you walked into an Apple store and asked them if they will give you a trade-in allowance for a two-year-old iPhone 4. They won't. You might get a few bucks for it on eBay or Craigslist but the lifespan of any electronic device these days is pretty short so you won't get much.
One year ago I bought a Galazy Tab 2 7.0", a tablet that is in most ways (GPS, camera, etc) much better than the Nook Tablet. It's running Android 4.2.2 (much later than the version of Android on the earlier Nook Tablets). I happened to stumble across Samsung's web page offering a credit for various Samsung devices toward a more recent (note that I did not say modern) product.
According to Samsung, my used Galaxy Tab 2 7.0" in excellent condition, with all accessories, is worth a $13 credit. Heck, the charger is worth more than that!
Note that the Galaxy Tab still does everything it used to (just like most electronic products), and compared to more recent products, I have no interest in selling it for much less than I paid for it ($200). Nevertheless, the marketing industry is convincing people that their children will go hungry if they don't have the latest and "greatest".. Of course, this means that they really don't have to offer much to those who just must have the latest, in order to convince them to upgrade.
$13 ??? Sheesh ...
[...] Nevertheless, the marketing industry is convincing people that their children will go hungry if they don't have the latest and "greatest".. Of course, this means that they really don't have to offer much to those who just must have the latest, in order to convince them to upgrade.
I recently passed my wife's NOOK Tablet over to my son after loading CyanogenMod on it. I was surprised at how usable that device still is. The single core NOOK Color definitely suffers with newer software, the but NT was still nice to use. I almost hated to hand it over. I just don't need another device.
To the OP: If you're on a budget, be sure the new device really offers something you really need or want before upgrading. The HD and HD+ are themselves older generation devices. Nobody seems to be sure what B&N plans on putting out next. You might be better off looking at a general purpose tablet.
Whatever you do, be sure to pass your older NTs on to somebody that can put them to good use! They still work very well for reading and lightweight applications.