Just check coupons out (with price alert and history). Do you want to know what the best price is?
Transmit distance: 150m (open)
Aliexpress
There’re some similar (or not) items on Aliexpress
| Image | Product (link) | Price | Coupons |
|---|---|---|---|
 |
Sonoff RF Brigde WiFi 433Mhz Wireless Signal Converter DW1 Door Sensor PIR2 PIR Motion Sensor for Smart Home | $6.38 | – |
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($8.02): BGSTHO15
2. ($8.50): BGAFF10OFF
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): elec, e2bcea, BG15Gadgets, SONOFF15, BG9NY, BGVDay10%off, BGTT10, bGhOnEy10, BGSMOFF, BGSONOFF15, BGELIG0920, 13f142, BgcLuBofErtA10, BGSONOFF16, BGCuponation10, BGHONEY2110, BG15Sonoff
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – SONOFF PIR2 Motion Sensor [EU/UK] ($-3)
Price history and price alert
Price history (for all/most countries) for SONOFF PIR2 Motion Sensor is here.
Price records source(s): Gearbest, 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)).