The only other company putting up a serious effort in the same niche is aiming at $150 (and releasing a month later than the AirPods) [1], so there's probably some lower bound here set by the complications of the hardware/R&D to seamlessly connect two separate earbuds through your head and to the phone.
[1]: http://www.theverge.com/2016/9/5/12798640/bragi-wireless-hea...