Amazon has 16 count Ivory Bar Soap for $3.79 with subscribe and save. In addition, they have a $.50 off coupon to clip at the bottom of the page. Pay $3.29 for 16 bars or $.21 each. Be sure to chose the subscribe and save option so that it can ship separately. You can cancel your subscribe and save at any time after the item ships.
Note: Amazon prices can change quickly, be sure to double check the price before you purchase.