As William Coyne said, "[A]fter you plant a seed in the ground, you don't dig it up every week to see how it is doing."
You may want to spend an amount of money optimally, but you have a control group designed not to do anything differently. That control group has some elements that you would want to spend money on. This lends itself to a modified Heisenberg uncertainty principle: you cannot optimize and be sure you have optimized simultaneously. Or more familiarly: if you're the best, you'll never know it. A setback for narcissists.