SoundPeats Audio via Amazon offers its SoundPEATS M20 3.5mm In-Ear Earphones with Microphone for $12.99. Coupon code "CVB7MPWY" cuts it to $6.99. Plus, Prime members bag free shipping. (Non-members can spend $35 or more to bag free shipping; otherwise, shipping adds $6.06.) That's the lowest total price we could find by $11. They feature in-line controls and a 20Hz to 20kHz frequency response.