Basically copy coupon, view price history or create e-mail price alert. What is best price?
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):
Power: 33W, Lithium-ion battery capacity: 2130mAh (built-in), Working time: 1 hours, Dust tank capacity: 0.6L
Price history and price alert
Check out price history chart (for all/most countries) for iRobot Roomba 890 Vacuum Cleaner.
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)).