I receive newsletters and ads from EVGA. They are offering a GPU trade in scheme also. I don't know how their scheme is structured, because I have no interest in upgrading at the moment.
If I'm not mistaken, EVGA has had a "trade-up" plan in place for quite a while, now.
Memory says since before last year, but I may be off on that recollection.
I can't see it being much of a motivation for me, though; since, when I do new builds, I shift the older systems to different tasks and all components stay in the system they were born-in.