Good for them. Some will call it an overpayment (they're not wrong in a vacuum), but its good business. That capital had to be deployed on the rotation, and there's very little opportunity cost over the next four years.
As we outlined late last week, you're looking for the first two years to mirror his 2019, and then accepting the fact that the final two could be average to spotty. However by then, Pearson, SWR, Manoah, Kloff, Kay, Borucki have a decent likelihood of having broke in \\ sticking \\ excelling, allowing him to slide down the rotation (or be on the IL). The theoretical dead $20MM is offset by the min contract performance of the young pitcher. Always, always, always better than using said young pitcher as capital to secure a veteran pitcher through trade.
This should not necessarily stop them from being opportunistic when it comes to Price. If its Boston retaining ~$5-7MM per season for the remaining contract, and at a middling prospect cost (something like a Logan Warmoth; i.e. no one in the top-15 prospects in the org), I'd be comfortable pulling the trigger.
Dickerson is likely holding out for multiple years, but he's always been the obvious left handed bat signing.
Merry Christmas you filthy animals.