Sarah is planning to buy apples for a pie. She finds that at Store A, apples cost $2 per pound, and at Store B, apples cost $3.50 for 2 pounds. Sarah needs 5 pounds of apples for her recipe. If she buys the apples from the cheaper store, how much money will she save compared to buying them from the more expensive store? Let's think step by step and output the final answer within \boxed{}.
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