If If the Buffalo Bills stay put at nine but still want to grab another top player in the 2019 NFL Draft, they could swing a trade to get back into the end of round one. There are financial incentives to doing so, as well as talent incentives, so the end of Round 1 picks can be more valuable than those at the top of the second round.
Financially, teams picking in the first round have the fifth-year option, keeping a player under team control for an extra year without breaking the bank. Instead of a franchise tag, the financial figure is much lower PLUS you have the option of franchise tagging a year later, giving the team six or even seven years of control over the player.