You can get a great value on multivitamins either through the big warehouse clubs, or simply in larger quantities from your usual grocery store. Multivitamin prices at Sam's Club are around 6.7 cents a pill, and stores like Walgreen's have prices closer 9.3 cents per pill [source: Switchyard Media]. But coming home with a bottle of 500 pills is only a good value if you plan to take them all, so keep expiration dates in mind. Depending on the amount of people in your household and how often they take vitamins, you may not be able to go through that large of a supply before the pills expire. In general, vitamin tablets last about four to five years, but expiration dates often vary by manufacturer [source: New York Times]. So calculate how much of a supply you need and purchase accordingly.