Aliexpress
Click here… to search for Xiaomi Bcase DSHJ-L-007 Rocket Mosquito Killer on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood.
Link: Banggood product page
Price: -3 USD
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!
Old coupons (from the oldest to the newest): vipupgrade8, TTxBG10, 2019SPEDM, BGDSHJ15, BGss8%hl, bgssaff9, AFfbG10, BGL00714, 0e7f33, BGHOMEG12, BGdfrt47, FBCOUPON1, BGSOTHING25, BG9FR01, BGHOMEA15%, BGAFF10OFF, BGCuponation10, 13f142, BGHONEY2110
(there’s a little possibility that old coupon will work)
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi Bcase DSHJ-L-007 Rocket Mosquito Killer.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).