Buy off amazon or aliexpress, usually price is better
If you are really after it and are unwilling to wait for delivery, try Jaben, call and ask.
Alternatively go to price.com.hk and search
Also I hope you mean ATH-M50x BT version, because I've never heard of audiotechnica mx50
https://www.amazon.com/Audio-Technica-ATH-M50xBT-Wireless-Bluetooth-Headphones/dp/B07HKVCVSY
$50 off $199 rn
(i strongly recommend if you want bt wireless just go with v-moda crossfade instead)