Toothbrushes may seem like strange items to buy in bulk, but even buying six to 10 at a time, instead of the just one, can add up to savings in the long run. For example, recently a box of six Oral B brand toothbrushes cost $13.88 at Sam's Club, while a box of two cost $7.99 at Rite Aid [source: Switchyard Media]. Dentists recommend that you start using a new toothbrush after three months, but the average American waits nine months to make the switch [source: Malitz]. So keeping a bulk supply can help improve your dental hygiene. You can also offer your extra toothbrushes as spares for forgetful house guests [source: Torabi].