To be fair to Mike, nomar, the big benefit of a move like that isn't replacing Jeter's D at short, it's replacing Tino's or Sierra's or Tony Clarke's or whoever's bat in the lineup with Beltre's.
So say it's Clarke you're replacing, and let's assume he was at least replacement level with the bat. You're probably picking up 25ish offensive runs over the course of the season. Considering how good the offensive already was, that translates to maybe 2 wins on a team that is already going to win between 90 and 100.
Taking that Beltre money and investing it in the pitching staff would probably yield a better return.
And you avoid upsetting the golden child.