Not an apples to apples comparison, but close. I just purchased a 2016 with 66k miles from a Toyota dealer in superb shape. New Michelin’s, no rust, functioning recirc door, every last bit of everything from new (remote for rear, covers for screens, literature, even the original window sticker), good maintenance... you get the idea.
I drove home for $53k. I paid more, but the mileage difference wouldn’t have a large value impact for me. Too similar.
I bought a very similar vehicle as an end user at what should be peak price for really not that much more than what your trade in is. Tax benefits outweigh the delta in fact.
Similarly, I found private sales for slightly cheaper than my purchase, but actually turned out to be more expensive after the dust settled. I don’t get my trade in tax break. I also financed a portion of the purchase, and if the loan saw full term, private party APR vs dealer APR = real money.
My point is, from a buyer’s perspective, I wouldn’t have purchased your truck even at $51k. I still think you should be able to get some negotiation on the trade in, but I don’t think it’s a “bad” offer. As others have mentioned, you can try CarMax or Carvana. They may get you a little better, but it will net negative after the lack of tax break on trading in.