Just check coupons out (with price alert and history). Let’s see what best price is ATM.
Power Supply: 2x AAA Battery, Range of Frequency: 2402MHz – 2490MHz, Resolution: 1600DPI, Package Contents: 1x Keyboard, 1x Mouse, 1x USB Receiver, 1x Keyboard Protect Film, 1x English Manual
Aliexpress
I could not find it on Aliexpress. Click here to search by yourself.
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. As you can see I didn’t find any active coupon for this product right now…
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!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): 502C6B, e2bcea, TTxBG10, e18b44, BG3CSUM, AFfbG10, BGBFCR02, BGCITYADS2019, BGVDay10%off, BGAFF10OFF, bGhOnEy10, BgcLuBofErtA10, 13f142, BGCuponation10, BGHONEY2110, BGraton, Cityads2213, BGc0ac93, keyboardMVC, Cuponation9, BGKBandmos12, BG73bf1a, BGff5312, BG975636
(probably won’t work, but you can try them out)
Price history and price alert
Check out price history chart (for all/most countries) for HK3600 2.4G Wireless Keyboard / Mouse Combo.
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)).