I agree to an extent, but sunk cost fallacy aside we're stuck with this guy, it makes more sense to see what we can get out of him than it does to simply dismiss whatever asset we may have in sandoval outright. As I said, we actually have very little depth at third base right now, our entire depth at 3b consists of players who could be moved to third base, including Shaw who was considered mostly a 1B prospect at the big league level until we got desperate, as well as possibly guys like Moncada or Swihart that could, one assumes, learn on the job. That's not fantastic depth to be dismissing a veteran starting player after a single poor year.
So it's not a financial reason so much as good asset and depth management, to see what we have with Sandoval, remove the emotions of last year from the equation and give him a fair chance, before making him the world's most expensive bench player, than it does to panic (and that's what this is, mindless, unreasoning, emotional PANIC) and move on to plan B without even trying plan A under the lights.