Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (569.99 USD): BGHU203
Coupon (579.99 USD): 150cb5
Coupon (725.39 USD): PICODICOM
(CouponsFromChina.com tip: apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Price history and price alert
Check out price history chart (for all/most countries) for FIIDO L1 48V 250W 23.4Ah Electric Bike.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).