Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. There is one coupon right now! Check this out.
Link: Banggood product page
Coupon (24.29 USD): BGProj
(CouponsFromChina.com tip: this code has to be applied in your cart 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): BGAProjector, Tabby20, BGprtecmundo
(there’s a little possibility that old coupon will work)
Price history and price alert
Check out price history chart (for all/most countries) for MIXITO Metal Anti-Light Projector Screen 110 Inch.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).