Aliexpress
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Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (25.85 USD): BGgh0525b
Coupon (27.25 USD): BG589b2e
(CouponsFromChina.com tip: this code has to be applied 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): BGca038e, BG23b788, BGHB218, BGMCL21, BGb351e0, BGcadcc0, BGHECARE1, BGec1f6d, BG4ee866, Cuponation9, 9OFFSUMMER, BG57423b, BG75597c, BGfee0d3, BG13136e
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Price history (for all/most countries) for USB UV Anti Fly Mosquito Killer Lamp is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).