If a team believes Jackson is true shutdown CB, a first round pick is just their opening offer. At his age, he is the Holy Grail for teams if they think he is a CB who can lockdown one side of the field. His salary won't be too high. And a first round pick isn't too much. It might be too little.
Almost every team is desperate for a lockdown CB. Other than QB, there is probably no position more valued in this league.
Right now, Jackson is the best CB in free agency. Statistically, he is an elite CB. The question is whether teams believe that he is actually an elite CB. If they do, you could see multiple teams willing to give up a first round pick for an elite CB who is only 26 years old.