Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. You can get coupon down below.
Link: Banggood product page
Coupon (54.89 USD): BGAFF10OFF
(CouponsFromChina.com tip: put item in your cart and apply coupon code there 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): BGkeyboard001, AFfbG10, bGhOnEy10, BGdragonBoat, BGSS10%SW, bgshOOp10, BgoFErTaSchInA10, BgcLuBofErtA10
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for MACHENIKE K7 87 Keys Mechanical Keyboard.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).