Where the teams are in the standings in late June will dictate whether these teams are buyers or sellers. We will just have to wait and let that play out.
As for the price for Beltre, maybe the Rangers demand Devers if they eat all of his 2017 and most of his 2018 salary, but not if the Red Sox are picking up the freight cost. If they want to clear a path for Joey Gallo, they might want to shed some payroll too. I doubt that they can land a Devers level prospect for a 38 year old who is owed $18 million for 2019 when he will be 39. Certainly, there is no downside to the Red Sox making an inquiry about Beltre as the season progresses, and we have a giant need at 3B. Other guys to inquire about would be Todd Frazier Moustakas.