$13.99 – 300m WiFi Repeater Signal Booster (Banggood, Aliexpress: Packing: 11.7cm * 11.7cm * 6.7cm., Name: 300M WiFi Repeater, Product: 8cm * 5.2cm * 7.5cm., Color: white / black, Technology: white glossy surface, Material: shell ABS (the best price with coupon)).
$13.99 – that is current price with coupon for 300m WiFi Repeater Signal Booster (in Banggood). Basically copy coupon, view price history or create e-mail price alert. What is the best price?
Latest price update (UTC time):
Banggood ($13.99)
Banggood warehouse is located in China. I have no active coupons for you right now. What about the price? From what I can see this price is higher than average price ($12.49).
Link: Banggood product page
Price: $13.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
Old coupons (from the oldest to the newest): BGae2847, BG589b2e, BGcb5ddb
(these codes were not working in latest coupon update, but you can check them out anyway)
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Here is price history (for all/most countries) for 300m WiFi Repeater Signal Booster. The lowest price was: $11.99.
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)).