As per MLB.com's Jim Callis, the Yankees have a total draft allotment of $5,831,200, which is the 24th highest in Major League Baseball. Their 1st round pick, 18th overall, has a slot value of $2,441,600. In 2015, those numbers were $7,885,000 and $2,543,300, respectively - the extra pool money came from a compensation pick for David Robertson signing with the White Sox. Here's a quick refresher on what these numbers actually mean (taken from the same link):
Each pick in the top 10 rounds comes with an assigned value, and the total for each of a team's choices covers what it can spend without penalty in those rounds. Any bonus money in excess of $100,000 given to an individual player selected in rounds 11-40 also counts against a club's bonus pool. The amounts rise each year in accordance with Major League Baseball's revenue growth and increased by 4.62 percent compared to 2015.
If a player chosen in the first 10 rounds doesn't sign, his pick's value is subtracted from his club's pool. If a team surpasses its allotment, it faces penalties.
A club that exceeds its pool by 0-5 percent pays a 75 percent tax on the overage. At higher thresholds, teams forfeit future picks: a first-rounder and a 75 percent tax for going beyond their pool by more than 5 and up to 10 percent; a first- and a second-rounder and a 100 percent tax for more than 10 and up to 15 percent; and two first-rounders and a 100 percent tax for more than 15 percent.