3 Brush Mode (Clean, Soft Massage, White), Vibration Frequency 31000 Per Minute, IPX7, 5V 1A / 5V 500mA, Working Time Max to 120 minutes.
Basically copy coupon, view price history or create e-mail price alert. What is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I found coupon for you. Check this out.
Link: Banggood product page
1. ($24.19): AFfbG10
you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): 50DGPO, 5c0a61, CPO7207, e51d07, 502C6B, 59c904, 0404digoo, vipupgrade8, TTxBG10, 2019SPEDM, bgssaff9, BGDigoo15%, BGYS220, BGYS221, BGBGHFRI15, 0e7f33, BGDG15
(these codes were not working in latest coupon update, but you can check them out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. China – Digoo DG-YS22 Sonic Toothbrush With 2 Heads Black ($-3)
Price history and price alert
Price history (for all/most countries) for Digoo DG-YS22 Sonic Toothbrush With 2 Heads White is here. The lowest price was: $12.99.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).