Thundeal TD50 Mini Projector 720p (Banggood, Aliexpress: Light source: LED, Standard resolution: Native1280x 720P, Light Source brightness: 5500Lumens, Color temperature: 16.7M, Projection technology: LCD, LED chip life: 50000, Support WiFi and Bluetooth-compatible, Supported video resolution: Max Support Full HD 1920*1080P / from HD source support 2K 4K, Contrast: 3000: 1 (the best price with coupon)).
Price history, coupons and price alert are available on this page. 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 and price update (UTC):
Banggood
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood.
Link: Banggood product page
Price: $-3
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!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
Old coupons (from the oldest to the newest): BGNTD55, BGProj, BG589b2e, BGe6ce32, BGSaleAD, BGProjcc
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for Thundeal TD50 Mini Projector 720p. The lowest price was: $84.99.
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)).