I think the point is being missed here. This response does not answer the direct brief nor the (more important IMHO) underlying question that attempts to excercise empathy for the customer:

"Rank the responses in the order of their relative concern with programming considerations, economic considerations, or other important considerations. If you were the programmer, which approach would you prefer? If you were Mary Jones, which approach would you prefer?"

After 20 years in industry, I constantly see people banging their heads against the wall, not understanding why the customer "doesn't get it," when in many cases they do in fact "get it" but the solution has different meaning to them. The complex challenge is identifying all of their underlying motivations and viewing the problem from their perspective.

Empathizing with the customer is the lesson, not the math. It's important because it makes for a happier professional relationship and if you're technically right, knowing the customer's drivers can help you efficiently negotiate the implementation path forward in a way that everyone is satisfied with and garuntees more future business. The lesson teaches a path to professional happiness, and that's invaluable. Who wants to be grumpy and angry 80% their life?