In Catalan there is an expression "ser la xocolata del lloro" that can be translated as "saving by not giving chocolate to the parrot is futile", conveying the meaning that when a household wants to save money, there are ways by which not much saving is going to be made. As an example, if you stop giving little bits of chocolate to the parrot to enjoy, although it looks like a saving measure, it's more posturing than real savings, so that doesn't make much difference: you actually won't end up saving much, because the amount of chocolate is very small.
Is there any equivalent expression in the English language for the same kind of saving efforts that won't make a difference?