Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. There is one coupon right now! Check this out.
Link: Banggood product page
Coupon (23.79 USD): BG75597c
(CouponsFromChina.com tip: put item in your cart and apply coupon code there 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): BGHB218, 2203ActiesNL, BGXPMA073, tRaDetRaCKeR, BGHECARE1, BG4ee866, BGc8055d, BG8ReviTrage, BGd12945, BGd1d443, 9OFFSUMMER, BG54a438, BG7163e6
(probably won’t work, but you can try them out)
Price history and price alert
Here is price history (for all/most countries) for TVAYA T1 Sonic Electric Toothbrush.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).