Is this, or is it not, the same Jason Bay that was dominant for the Pirates before he came to Boston?
For the record, I think bringing back Beltre is, at this point, more important than bringing back Victor Martinez. If only because Beltre is more likely to still be playing third base regularly in 4 years, which is the likely minimum length of either player's new contract. I have no problem with letting VMart go for a pick and "figuring something out" at catcher, if you start with the presumption that VMart may not catch for much longer. Beltre on the other hand is elite at his position, at least this year, and if his price isn't a killer I'd like to see if he can do it again a few more times. He's had no real issues with his health and while I don't think he'll be as good as he was this year, he should still be more than serviceable. Vmart is much less likely to still retain his value by year 3.
Theo deciding to bring Salty in rather than a similar young 3B suggests to me that he's made the same call. He's putting himself in position to replace at catcher. And it's entirely possible that Lavarnway will force his hand in the next couple years too, he's looking fantastic, especially offensively.