Aliexpress
Click here… to search for Digoo DG-C10 Backlight Projection Clock on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (16.67 USD): BGAFF10OFF
Coupon (16.67 USD): bGhOnEy10
(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): 50DGC10, C799, C10799, 502C6B, 0404digoo, e2bcea, TTxBG10, BGDigoo15%, BGPDGC10, BGDG899, AFfbG10, BGDGC107, BGFDGO49, BG788C10, BGC1077, BGBFAFF2019, BGCITYADS2019, BGDG15, 20%DG422
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for Digoo DG-C10 Backlight Projection Clock.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).