Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (130.89 USD): BGPROBuscape
Coupon (138.59 USD): BGAProjector
(CouponsFromChina.com tip: just apply this code 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): ViviC80UP, e2bcea, TECH8%, PICODICOM, BG3CSUM, BGPAYPALSS, aff7off, BGaDmITAd, bgchinafest, BGBFAFF2019, BGCITYADS2019, 7bcdf9, bGpAnDacHeCk, Email5, bGhOnEy10, BGdragonBoat, BGAFF7OFF, bgshOOp10, BgoFErTaSchInA10, BGAFF10OFF, BGProjectors
(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 ViviBright C80UP 1/8GB Projector? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).