Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. There are no active coupons for this product, but the price is pretty low isn’t it?
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): BGHB218, tRaDetRaCKeR, BGHECARE1, BG4ee866, BG81d3c6, BGHOM053, BG8ReviTrage, BGd7212c, Cuponation9, BGa9486b, BGce8e2d, 9OFFSUMMER, BG75597c, BG0c0c72, BG589b2e, BG0328f
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for Enchen T501 Electric Toothbrush.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).