Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I can’t find any active coupons for this product 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!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGAK51017, TTxBG10, BG3CSUM, bgssaff9, AFfbG10, 502C6B, BGBFAFF2019, BGCITYADS2019, BGMPB2020, BGAFF10OFF, bGhOnEy10, BgoFErTaSchInA10, BgcLuBofErtA10, BGCuponation10, 13f142, BGHONEY2110
(probably won’t work, but you can try them out)
Price history and price alert
Here is price history (for all/most countries) for Ajazz AK510 Retro Mechanical Keyboard.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).