You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Model: SOUTHSUNNY, Dimensions: 7.5″ Hx 3.5″ Wx 3.88″ D, Effective Range: 5000(167km) feet in redius, Ultrasonic Frequency: 15KHz-25KHz(Adjustable), Working Current: ≤250mAh, Output: 9V DC, Power Supply: 6×1.5V C-size Battery, Motion Sensor Distance: ≤150feet(5km)
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 code price check (UTC time):
Banggood
Banggood warehouse is located in Europe 
. There’s only 1 record in my database, so I have no idea if the price is OK.
Link: Banggood product page
1. ($20.23): BGf625a4
2. ($21.61): BG589b2e
you should apply the coupon 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): BGdc6b98, BG268b7b, Cuponation9, BG8ReviTrage, BG00c906, BGdbe184
(these coupons are old, so probably won’t work)
Price history and price alert
We don’t have enough records in database to show price history for this item. BTW: We have only recorded this price: $15.99.
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)).