Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. Too bad there’s no coupon right now 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
There were country-specific coupon codes published on Couponsfromchina social channels and price alerts. Coupon price may vary by country, because there’re different VAT rates, shipping cost etc. There is a chance that some latest coupons are still working:
Old coupons (from the oldest to the newest): BGkj58d, BG3CSUM, bgssaff9, BGCPP009, AFfbG10, BGVDay10%off, Email3, BGAFF10OFF, BGTT10, bGhOnEy10, BGdragonBoat, BANGGOODSD
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Here is price history (for all/most countries) for Geek GK64 Mechanical Keyboard.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).