Just check coupons out (with price alert and history). Let’s see what best price is ATM.
Power: 5W, Base size: 13.5*13.5*3.7cm/5.31*5.31*1.45inch, Material: ABS, Color: White/Grey, Voltage: 3000V, Type: Mosquito Swatter, Lithium battery: 1200mAh, Size: 49.5*18.5*4cm/19.45*7.27*1.57inch, Frequency: 50Hz, Net Weight: 470g/16.58oz, Quantity: 1PC
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in Europe 
. I don’t know if this is a good price – number of records in my database is too low!
Link: Banggood product page
1. ($15.66): BG14d38d
2. ($16.99): BGHECARE1
apply code in your basket (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): BGHB218, BGCZM818
(system checks these coupons on every price check (like once per 24 hours), 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: $14.99.
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)).