Xiaomi Mijia Wowstick Magnetizer Demagnetizer (Banggood, Aliexpress: Control Channels: 2 Channels (Magnetizer / Demagnetizer) (the best price with coupon)).
Just check coupons out (with price alert and history). What is best price?
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 China. There is one coupon available! Pretty cool, huh?
Link: Banggood product page
1. ($4.15): BGGines
this code has to be applied in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
Old coupons (from the oldest to the newest): 440822, 502C6B, 20tools, 38fdec, BG1534, BG2WOW2, AFfbG10, BGOMG2, BGWowstick2, BGWOWBT, BGPowerTool15, BG2020NS, BGWM2, BGWowstickFB, BG2MFC, BGherra, BGPTOOL, BGWow101, BGPToo15, BGWOWSK15, BGETS3, BGPower15off, BG123FBR, BG123F2021, BGPTL088, BGTDL01, BGb48356, BG589b2e
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – Xiaomi Mijia Wowstick Magnetizer Demagnetizer [EU] ($-3)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi Mijia Wowstick Magnetizer Demagnetizer. The lowest price was: $0.79.
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)).
. I can’t tell you if this price is good – not enough records in my database, so I won’t judge. Well, there is one coupon available right now.