That sold a couple months ago in a PWCC auction for $25K. That's one of his key rookie cards.
That Lamar Tie-Dye I linked a little ways up. Auction still has a couple more days.
Lamar's cards went down because he came back to earth last season after his MVP campaign. All young players have price swings and if they struggle for a little bit or have a "down" season, prices will reflect that. People are still buying into the "what if" with all these young QBs, including Mahomes.
Before last season, Lamar Jackson's National Treasures RPA was selling for more than Russell Wilson's. That's insane but also how the card market works. Established Hall of Famers have a certain ceiling until they start to rack up more rings.
If any of these young QBs (Allen, Jackson, Herbert, Burrow, Murray, Mayfield, etc.) have slow starts this year, it'll take a while to recover. Think how quickly things have fallen apart for Goff and Wentz. Now their RCs are dirt cheap even though one went to a Super Bowl and the other was on his way to an MVP before he got injured.