If you make a policy of ignoring individual things because the cost in isolation is trivial, the sum of those ends up not being trivial. Or, as is popularly misattributed to (but endorsed by) Senator Everett Dirksen: "A billion here, a billion there, and soon you are talking about real money".

For reference, the US Federal budget in 2015 was 3.7 trillion dollars. [1]

[1] https://en.wikipedia.org/wiki/United_States_federal_budget