$36.99 – eWelink APP WiFi Smart Valve Water Gas Shutoff Automated Ball Valve DN15/DN20/DN25 Wireless Control for Alexa GoogleAlice – DN25.
You can get eWelink APP WiFi Smart Valve Water Gas Shutoff Automated Ball Valve for $36.99 with coupon (from Banggood). Basically copy coupon, view price history or create e-mail price alert. What is the best price?
Latest coupon code price check (UTC time):
Banggood ($36.99)
Banggood warehouse is located in China. Isn’t it too expensive? Actually this is the best price in history according to CouponsFromChina database! Well, there is one coupon available right now.
Link: Banggood product page
Price without coupon: $38.99
1. ($36.99): BG3e8873
coupon code has to be applied in shop’s cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
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.
Price history and price alert
Price history (for all/most countries) for eWelink APP WiFi Smart Valve Water Gas Shutoff Automated Ball Valve is here. The lowest price was: $36.99.
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)).