12. JA Happ: Two Years, $34 Million, 2018-19 Offseason
The Yankees don't like letting players they've traded for at the previous deadline walk during the next free agency cycle, even if all it took to acquire them was a Brandon Drury (mid-blindness) and Billy McKinney package.
In fact, when 2018 ended, the Yankees had played the JA Happ thing perfectly -- except for the part where his hands trembled on the mound at Fenway Park for Game 1 of the ALDS.
Alas, they tied up their payroll with two additional years and $34 million of Happ money for 2019 and 2020. Having Happ's money on the books more than likely prevented the Yanks from doing anything around the Gerrit Cole signing to make the team better, a frustrating bugaboo even in hindsight knowing that the 2020 season was mostly wiped away.
And, though it's not a binary, Brian Cashman decided, "$17 million for Happ? Yes! $25 million for Bryce Harper? No way!" before watching Happ go 12-8 with a 4.91 ERA in 2019, firmly teetering on Burnett territory.