As for the non-bolded part, we've been rehashing the same argument, so there isn't much sense in continuing this. I see your point, and I see Jeter's point (and I don't blame him), but I also don't blame the Yankees for going with what gives them the best chance to win.
As for the bolded part, it's more about the years than anything. Having Jeter at SS and hitting leadoff four years from now would be a bad thing for this team. It's also not about spending less money, but spending that money correctly.