Aliexpress
Click here… to search for AUN AKEY8 1080P Projector on 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 (252.44 USD): BGPROBuscape
Coupon (267.29 USD): BGAProjector
(CouponsFromChina.com tip: you should apply the coupon 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): 7bcdf9, BGANAK8, BGProjectors
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for AUN AKEY8 1080P Projector.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).