The New York Jets already knew they would have to pay big money to sign prospective free agent Kirk Cousins. Thanks to Jimmy Garoppolo, they now have a better idea of the starting point.

Thursday's report of Garoppolo agreeing to a five-year, $137.5 million contract with the San Francisco 49ers, which makes him the NFL's highest-paid player, sets the floor for the Cousins negotiations in terms of average per year -- $27.5 million.

If Garoppolo, he of seven career starts, is getting that much money, how much will Cousins seek? Clearly, his resume outshines that of Garoppolo, based on individual performance. It's safe to assume Cousins' contract will reach at least $30 million per year, so with a five-year deal, we're talking about the first $150 million player.

Of course, the important number is the amount of guaranteed money. The full scope of Garoppolo's contract hasn't been reported yet, meaning the structure and amount of guaranteed money, but one detail has emerged: It includes $90 million over the first three years. Clearly, the 49ers are betting big on his potential.

Garoppolo surpassed Matthew Stafford ($27 million), who had surpassed Derek Carr ($25 million), as the highest-paid player. When Cousins signs his new deal, he'll leapfrog them all. (We're assuming the Washington Redskins don't use the franchise tag for the third straight year, which has been discussed.) What do all four quarterbacks have in common? Not one of them has won a playoff game.

By the time the seasons starts, Cousins could be the third- or fourth-highest-paid quarterback because Aaron Rodgers, Matt Ryan and Drew Brees (a free agent) are in line for new deals.

What the Jets have to ask themselves is whether Cousins is worth the money.

The positives: He's a durable, productive passer (three straight 4,000-yard seasons), and he'll be only 30 years old by the start of next season. He's a known quantity, and that really appeals to the Jets. It's rare that a quality quarterback, with no injury questions, hits the open market. If they can sign him quickly, it might help attract other free agents. They could save their draft choices, including No. 6 overall, to address other pressing needs.

The negatives: The cost. The difference between signing Cousins and drafting a quarterback with the sixth pick is an estimated $57 million in cap space over the first three years. He's not a proven winner -- 26-30-1 as a regular-season starter, 0-1 in the playoffs. He'd be a win-now quarterback on a team still in the throes of rebuilding.

This much is clear: Whether it's with the Jets or another team, Cousins will land a historic contract -- until someone else makes history.