These Crest 3D White Professional Effects Whitestrips drops from $54.99 to $39.99 with free shipping at Drugstore.com. Plus, new customers can use code 195176A2 to save $5 off, which drops the price further to $34.99 (or pad your order over $50 to save $10 off). Next, send off for this $10 Mail-in Rebate for a net price of $24.99 shipped. The best price we could find for this quantity anywhere else is $38. Twenty treatments are included. Sales tax is charged in most states.