Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I have no active coupons for you right now.
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): Email5, BG3DP09B, 7d18f7, 13f142
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for QIDI X Maker 3D Printer.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).