Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. We have found one coupon for this product!
Link: Banggood product page
Coupon (308.99 USD): 13f142
(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
Old coupons (from the oldest to the newest): BGYP73A8, Email5, BGYPA9, BGYP73A9, BGYP3A13, BGYP3A14, 7d18f7
(probably won’t work, but you can try them out)
Price history and price alert
Do you need price history chart (for all/most countries) for YEPO 737A8 N4100 8/256GB? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).