These numbers are based off opening day payroll
2018 Red Sox 235.65M (1st)
2017 Astros 124.4M (18th), add 20M after Verlander trade
2016 Cubs 116.6M (14th)
2015 Royals 113.6 (16th)
2014 Giants 154.2M (7th)
2013 Red Sox 150.6 (4th)
Looks to me like only the Red Sox are buying...