Yeah what does it matter if he'll only DH this season? That's probably his best position anyway.
In the offseason Bregman could walk so perhaps 3B would be possible, but if not it seemed like Devers would be open to 1B. But I don't think they'd need him to anyway, he could just DH.
And yeah, maybe he's expensive for a DH but he's a Top 15 hitter in baseball and this is the Boston Red Sox. They should have a payroll right near the Yankees and Mets. Instead they are trying to save money.