The link doesn't tell you that trade in is available, but I walked in yesterday, saw it, and went to trade in this morning, and got it.
My 2-year-old controller traded in for $50.95 since I paid $49 for a $99.95 PS4 500 Million Limited Edition Controller, which could cost more in eBay (if you get what I mean).
It's a Limited Edition, they only made 500 million of these controllers.