Basically copy coupon, view price history or create e-mail price alert. Let’s see what best price is ATM.
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
1300 ANSI bright for clearly display in daytime, Auto focus technology for convenient operation and stable image quality, WiFi: 2.4GHz + 5GHz, 8000: 1 – 9000: 1 contrast ratio for clear image display in daily time, 45 degrees horizontal and vertical keystone correction for breaking limit of placement, Miracast, 1.1: 1 throw ration for large image in short distance, 3D display for an immersive experience, Built-in dual 5W speaker for HiFi sound, 50 – 300 inch projection size for various occassion use (best size: 120 inch), LED light serves up to 30, about 10 years on average (8h for each day), quad-core, 000 hours, Mirroring: Airplay, Memory: 2GB DDR3 + 16GB eMMC, CPU: Amlogic T968, Parameters, Operation system: Android 5.1
Price history and price alert
Do you need price history chart (for all/most countries) for JMGO N7 DLP Projector? There we go.
Price records source(s): Gearbest
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)).