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).
Just check coupons out (with price alert and history). Let’s see what best price is ATM.
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.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in Europe 
. I’m not sure about the price, coz I have only 1 record(s) in my database.
Link: Banggood product page
1. ($20.23): BGf625a4
2. ($21.61): BG589b2e
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGdc6b98, BG268b7b, Cuponation9, BG8ReviTrage, BG00c906, BGdbe184
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
It doesn’t make sense to generate price history chart, because there is one price record which is: $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)).