Aliexpress
Here are coupons that you can use.
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. China – Digoo DG-YS33 Sonic Toothbrush Black (-3 USD)
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. One coupon is available. Cool!
Link: Banggood product page
Coupon (16.35 USD): AFfbG10
(CouponsFromChina.com tip: coupon code has to be applied in shop’s 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): YS310, TB159, 3776eb, 0404digoo, e2bcea, vipupgrade8, TTxBG10, bgssaff9, 502C6B
(you can check these old coupons out, but these probably won’t work)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. China – Digoo DG-YS33 Sonic Toothbrush Black (-3 USD)
Price history and price alert
Price history (for all/most countries) for Digoo DG-YS33 Sonic Toothbrush White is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).