Go down and check coupons out. Remember to check price history if it is available. Let’s see what best price is ATM.
Interface: USB2.0, Speed: 300Mbps, Dimension: 12x 3x 0.5cm, Weight: 35g
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($11.56): BGAFF10OFF
2. ($11.56): bGhOnEy10
just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): 502C6B, TTxBG10, BGRepeater, BG3CSUM, AFfbG10, BG455XM4C, BGCVTUY8N, BGBFAFF2019, BGhjiff5io, BGCITYADS2019, BGN355P
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi 300Mbps Wifi Amplifier Chinese.
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)).