Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. We have found one coupon for this product!
Link: Banggood product page
Coupon (8.09 USD): AFfbG10
(CouponsFromChina.com tip: apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): 684fa7, e2bcea, TTxBG10, 2019SPEDM, BGITCH544, 502C6B, BGBFAFF2019, BGCITYADS2019, BGBGHFRI15
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for Mosquito Bite Helper.
Price records source(s): Gearbest, Banggood
Click on image to enlarge.
You can set price alert (for Banggood).