Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. Only one coupon available!
Link: Banggood product page
Coupon (17.29 USD): 00c906
(CouponsFromChina.com tip: apply code in your basket (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): 131a07, 0404digoo, 502C6B, e2bcea, vipupgrade8, TTxBG10, BGss8%hl, bgssaff9, AFfbG10, BGDSF69, BGORE2, BGpldigoo6, BGDOC88, BGC4SS, BGDigoo15%, BG59C4S, BG559C, BGBAPOHG, BGTY2K, BG457R, BGHOMEG12, BGDG15, BGdigoo15, BGAFF10OFF, bGhOnEy10, 20%DG422, BGdragonBoat, BGSS10%SW, BGDGASG, BGHome15%, BGHOMEA15%, BgcLuBofErtA10, BGHBHJ105, BGCuponation10, 13f142, BGHONEY2110, BG10OFFAFF, BGwhielabel, BG10OFFAFF1, BANGGOODSD
(probably won’t work, but you can try them out)
Price history and price alert
Here is price history (for all/most countries) for Digoo DG-C4S Alarm Clock.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).