Duduma via Amazon offers its Duduma Unisex Polarized Sport Sunglasses in 10 styles (Black/Black pictured), model no. TR90, for $21.99. Coupon code "F7VRNJ2V" cuts them to $11.99. Plus, Prime members receive free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $5.48.) That's the lowest total price we could find by $14. They feature 100% UVA and UVB protection, shatterproof lenses, and a super-light frame.