Como dizer "Economia porca" em inglês

You get a bus and pay 5 dollars instead of a taxi for 7, 8 dollars. Got it? You save 2 or 3 dollars, but it's not worth it.

Then those 2 - 3 Dollars, is a saving that isn´t worth it.
You can make it a personal opinion, by stating that "is a saving that isn´t worth it, to me."

Para dizer "uma economia pequena (de dinheiro)", "uma economia mínima", "uma economia quase insignificante", "uma economia porca" em inglês, sugiro as seguintes opções:

• Minor saving(s)
• Very small saving(s)

Exemplos de uso de publicações internacionais:

• So it's a minor savings (like 10-25 cents) but hey it's something!
• It's a minor saving but a saving nonetheless. Here's the recipe for spicy tomato sauce.
• It is a very small saving, surely there is somewhere else they could find that amount of money without hitting the most vulnerable of families.
• My diesel pickup is still cheaper to drive than a petrol model would be, but it's a very small savings.

Bons estudos.