The "production per dollar" argument is real. Based on the cost of incremental FA WAR, I'm pretty sure both of these guys will be worth more than they sign for.
But the obvious issue when you do the Jay's napkin math...is that without a big bump in payroll and resigning them, we will lose a lot of value as we just haven't produced enough cheaper controllable talent. We traded it off, drafted poorly or didn't develop well. Pick your poison.
If we had these assets, we could have let one or both walk and mixed in the younger players to backfill at least some more of the lost production...much like the Cards did with Pujols.