The Boras twins, Ells and Drew, are undoubtedly gone. Boras can get blood out of a turnip, and he will get some team to overpay beyond what the Red Sox will pay--for two replaceable guys. Most likely, he will get them multi year deals which won't make sense for the Red Sox.
Besides, the Red Sox have won their championship--no team ever repeats--the cards have to fall in place just right, and that never happens two years in a row. The exception were the mercenary Yankee teams of the late 90s, when they were outspending everybody by an even larger margin than today. Plus they had some excellent homegrowns like Jeter, Posada,Rivera, etc., they don't have today.
I think the Red Sox have the luxury of not feeling desperate to sign free agents. They should, however, retain the chemistry that fell into their laps this year. That means they should know who the key players were: I would say Vic, Lackey, Lester, Koji, Nap, Gomes, Ortiz, Pedey--maybe Buchholz, Ross, Nava, Carp. They have the luxury of putting a Bradley in CF and Bogaerts at SS, Middlebrooks at 3B, and let them develop.
One thing Cherington needs to do is to define the core chemistry and keep it. His first mistake will be to change it, or upset it. Successful GMs make that mistake all the time. The Yankees never make that mistake.