REI offers the Sawyer Premium Maxi DEET 0.5-oz. Insect Repellent for $1.93. Choose in-store pickup to avoid the $5.99 shipping fee. That's the lowest price we could find by $6. This 98% DEET solution fends off mosquitoes, biting flies, chiggers, ticks, fleas, and gnats for up to 10 hours.