Aliexpress
Click here… to search for Alfawise S100 Sonic Toothbrush Heads 2pcs on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Price history and price alert
Check out price history chart (for all/most countries) for Alfawise S100 Sonic Toothbrush Heads 2pcs.
Price records source(s): Gearbest
Click on image to enlarge. 
You can set price alert (for Banggood).