Aliexpress
Click here… to search for HKC C4000 23.6 inch Curved Screen on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Price history and price alert
Price history (for all/most countries) for HKC C4000 23.6 inch Curved Screen is here.
Price records source(s): Gearbest
Click on image to enlarge. 
You can set price alert (for Banggood).