Let's choose a value of \( d = 50 \).
For Present 1, the cost is \( d + 10 = 50 + 10 = 60 \).
For Present 2, the cost is \( d - 15 = 50 - 15 = 35 \).
For Present 3, the cost is \( d \times 1.5 = 50 \times 1.5 = 75 \).
For Present 4, the cost is \( d / 2 = 50 / 2 = 25 \).
Winona and Takoda should consider buying Present 3, which costs $75. This option presents a balance between a higher cost and perceived value. Present 1 is the most expensive at $60, while Present 2 is the cheapest at $35. Present 4 is the least expensive at $25, but it may not offer the desired quality or appeal to the recipient. Present 3 strikes a good balance by being reasonably priced while still offering good value for money.