Redori via Amazon offers Amazon Prime members the Bell Kid's Maniac Multi-Sport Helmet in Danger (pictured), model no. 111660, for $5.99 with free shipping. (Non-members can spend $25 or more to qualify for free shipping; otherwise, shipping costs $5.58.) That's the lowest total price we could find by $5. This adjustable helmet is designed for kids 8 to 14 years old. Note: It's also available in Symbol, model no. 111659, for $6.07 with free shipping for Amazon Prime members.

Amazon Prime membership is $79 per year; however, Prime is free for college students for one year, and free for parents and caregivers for three months.