MLB ownership is as much about "the club" as it is about maximizing the money. This is why MLB set a maximum bid for Washington franchise - they did not want Soros to be the high bidder. They also take care of execs who don't necessarily have the money but who have been good for baseball. This explains both Lucchino and Kasten, and probably the new owners of SD as well.
With the Red Sox, the Werner - Otten - Lucchino group did not really have the money to outbid some local bidders, but because the Sox were owned by a charitable foundation, they needed to make the bid respectable. Loria wanted out of Montreal, who they wanted to contract, so they worked out the dela where MLB bought Montreal, Loria bought Miami, and Henry was brought in to the Werner group. With that, they outbid O'Donnell and McCourt (who offered prime land for a new stadium on the waterfront in lieu of some cash), or at least got close enough so the Yawkey Trust could make the sale. Henry has won two of the best pro sports franchises (Red Sox and Liverpool) without being the top bidder for either.