A:Answer Unfortunately, this is not a cut and dry answer, as the trade in value can change from day to day. There is a link at the bottom of the Best Buy website that allows you to get a trade in estimate, however, even that is not a 100% guarantee, because it is dependent on a visual inspection of the device at the time of upgrade. Currently, there are no trade in promotions running with an S8 or S8+ purchase, so the Note 4 would be worth the base trade in value, and that would come to you on a Best Buy gift card.