System Android 9.0, Resolution 2560X1600, CPU HiSilicon Kirin 980 Octa Core up to 2.6GHz, GPU Mali G76 720MHz, RAM 4GB, Screen 10.8 inch IPS Screen, Capacity 64GB.
Just check coupons out (with price alert and history). 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.
Link: Banggood product page
1. ($422.99): Email5
2. ($422.99): bgshOOp10
apply it 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): BG40d1c0, aff7off, BGf6df0c, bgchinafest, 7bcdf9, BG6ca9e2
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Check out price history chart (for all/most countries) for Huawei M6 CN 4/64GB WIFI Tablet Gray. The lowest price was: $378.99.
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)).