Just check coupons out (with price alert and history). What is best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
| Image | Product (link) | Price | Coupons |
|---|---|---|---|
 |
Smart Automatic Watering System Plant Waterer for 10 Potted Plants Waterproof DIY Drip Irrigation Kit with LED Display Timer | $30.86 | – |
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Size: 110*33*29.5mm/4.33*1.29*1.16inches, Working Time Range: 1-999 seconds, Weight: 90g/3.17Ounce, Countdown Range: 1-999 hours, UI water pressure: ≥30psi (200kpa), Input Voltage: 5V, Water flow: 0.2-0.4LPM, Rated current: ≤800mA,
Banggood
Banggood warehouse is located in China. Only one coupon available!
Link: Banggood product page
1. ($31.95): BG00c906
coupon code has to be applied in shop’s cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG0eead6, tRaDetRaCKeR, BG36610f, 8wEbgaInS5, BG505b8f, BG4501c6, BGa63c81, BGMX278, BG6ac00a, BGbb2e8a, BG3529e1, BG7d77a3, BGad5f82, BG94a9f4, BGa78c8c, BGa3ac8d, BG02e13c, BGc616b7, Cuponation9, BG8ReviTrage, BGcoupon8off, BGGutscheine
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for Smart Automatic Plant Waterer Drip Irrigation System Timer.
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)).