You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Rated Voltage 3.6V, 2A, Standby Time 13 Days, Charging Temperature 0℃-45℃, VHF, Battery 5200mAh (18.72Wh), Receiving Sensitivity -122dBm (12dB sinad), Waterproof IP65 Waterproof, Antenna length 120mm, Audio rated power 500mW, Operating Temperature -20℃-50℃, Display Module 1.77inch LCD Screen, Length of Use 15h, Input Parameters 5V, Transmit Power 0.5W / 3W / 5W, Size 57.8x 29.2x 258mm, UV Dual Band UHF, Range 1-6KM, Item Xiaomi Mijia 2S Walkie Talkie, Interface type USB Type-C
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): 502C6B, e2bcea, TTxBG10, BGOD1, AFfbG10, BGCITYADS2019, BGMPB2020, BGAFF10OFF, bGhOnEy10, BGdragonBoat, BGSS10%SW, bgshOOp10, BGELIG0920, BGTT10, BgcLuBofErtA10, BGSHHA, BGCuponation10, BGHONEY2110, 7bcdf9
(there’s a little possibility that old coupon will work)
Price history and price alert
Price history (for all/most countries) for Xiaomi Mijia 2S 5W Radio Walkie Talkie is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).