This is a common feeling

On PS questions I always WRITE DOWN what the question is asking BEFORE I take a step back to consider how to solve. If you jump straight into algebra without knowing why, you probably won't realize when you've actually found your answer, and you might miss a faster method of solving.

Especially for word problems, you have to go over every word carefully since even a small phrase can radically change the question.

FACT: Customer charges 1 hour for calls to Country A
QUESTION: What is the MAXIMUM he could have saved? (Meaning how expensive can we make the calls?)

Remember that on the GMAT they don't usually give you extraneous information unless it's necessary to solve. Why would they tell us the different prices for 3 minutes and then the minutes thereafter unless we needed it to solve?

Even after seeing the answer I still find this question confusing. Why is the $.80 not used in the discounted option, e.g 25+.6*3*1.60+.6*57*.80? What constraint prevents that from being the cheapest option?