Aliexpress
Click here… to search for Tanix TX9S S912 2/8GB TV Box on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. Hmmm… There is no active coupon in Banggood at this moment.
Link: Banggood product page
Price: -3 USD
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Old coupons (from the oldest to the newest): elec, BGBFAFF2019, BGCITYADS2019, bGhOnEy10, BGVSTX9S
(there’s a little possibility that old coupon will work)
Price history and price alert
Here is price history (for all/most countries) for Tanix TX9S S912 2/8GB TV Box.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).