Aliexpress
Here are coupons that you can use.
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. China – SONOFF BASICZBR3 Zig.Bee Smart Switch (-3 USD)
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in Europe 
. There’s only 1 record in my database, so I have no idea if the price is OK. One coupon is available. Cool!
Link: Banggood product page
Coupon (7.64 USD): BGSmart6
(CouponsFromChina.com tip: put item in your cart and apply coupon code there after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): elec, BGBFAFF2019, BGCITYADS2019, BGE13, BGTT10, bGhOnEy10, BGSMOFF, BGSONOFF15, BGELIG0920, 13f142, BgcLuBofErtA10, BGSONOFF16, BGAFF10OFF, BGSTHO15, BGHONEY2110, BGSHOM15, BGSHE15, 6GSGIT, BG15Sonoff
(probably won’t work, but you can try them out)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. China – SONOFF BASICZBR3 Zig.Bee Smart Switch (-3 USD)
Price history and price alert
It doesn’t make sense to generate price history chart, because there is one price record which is: 5.99 USD.
You can set price alert (for Banggood).