With orders of $25 or more, Amazon offers the One-A-Day Men's Pro Edge Mulivitamin 50-Count for $5.10 with free shipping. (Non-members can spend $35 or more to qualify for free shipping.) That's the lowest total price we could find by $3. It purports to support healthy muscle function.
Note that this item is part of Amazon's "add-on" program and can only be purchased with an order of $25 or more.