Size: 42.6×42.6x20mm, Output: AC100-240V 50/60Hz 10A Max, WIFI: IEEE 802.11 b/g/n 2.4GHz, Model: MINI, Input: AC100-240V 50/60Hz 10A Max, Material: PC V0.
Go down and check coupons out. Remember to check price history if it is available. Let’s see what best price is ATM.
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.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in Europe 
. I don’t know if this is a good price – number of records in my database is too low!
Link: Banggood product page
1. ($35.00): tRaDetRaCKeR
2. ($35.00): 8wEbgaInS5
3. ($35.00): pROMo8cuPoN
4. ($35.38): 2203ActiesNL
you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): elec, BGE13, BGVDay10%off, bGhOnEy10, BGSMOFF, bgshOOp10, BGSAMRTH, BGELIG0920, BgcLuBofErtA10, BGSONOFF16, BGAFF10OFF, BGSTHO15, BGCuponation10, 13f142, BGHONEY2110, BGSHOM15, BGSHE15, BG34cd45, 6GSGIT, ADMITAD2212, BGc5d108, BGSmart6, 8BGwbg2204, BG15Sonoff
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. China – 5Pcs SONOFF Two Way Smart Switch 10A ($-3)
Price history and price alert
Well, you won’t see price history chart, coz we have only 1 database record for this item (and price was $30.43).
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)).