repelling ultrasonic frequency is 22 – 65KHz and the effective range is 80 – 120sqm.
Basically copy coupon, view price history or create e-mail price alert. What is best price?
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 price update (UTC time):
Banggood
Banggood warehouse is located in China. Too bad there’s no coupon right now 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!
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGLOS07, AFfbG10, 502C6B, BGBFAFF2019, BGCITYADS2019, BGBGHFRI15, BGVDay10%off, BGHOMEG12, BGMPB2020, BGWIUQEF, BGAFF10OFF, bGhOnEy10, BGdragonBoat, BGSS10%SW, BGHome15%, BgcLuBofErtA10, BGHONEY2110, BG10OFFAFF, BGwhielabel, 13f142, BG10OFFAFF1, BANGGOODSD
(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 Electronic Pest Reject Repeller. The lowest price was: $2.49.
Price records source(s): Gearbest, 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)).