There's been some discussion of this in the Nook forum, but I thought it might be of interest to a larger audience.
Best Buy is having another
trade-in promotion where you get a minimum $50 gift card for any working tablet (other than a Nook) plus a $50 coupon toward the purchase of a new Tab S2. Limit two trade-ins per customer, but you can only use one coupon per purchase.
It's important to note that the stated trade-in value is irrelevant. I traded in two HP Touchpads which according to the website have no trade-in value and got my $100 gc. It's a pity you can't stack the coupons because then I might be tempted, but I'm more than happy with the credit.
The promotion runs through September 26.