Just check coupons out (with price alert and history). You probably want to know what is the best price?
Product Model: RadicalGel 661/05, Nib: 0.4mm, Quantity: 12 pieces, Material: ABS
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. I don’t think there is an active coupon right now – at least in my database.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): 12annvex-8%, 7f09ac, e2bcea, BGMLSwiss, 2019SPEDM, BG3CSUM, AFfbG10, 502C6B, BGBFAFF2019, BGCITYADS2019, BGVDay10%off, BGAFF10OFF, BGTT10, bGhOnEy10, BGRA582, BGRAX582, BGdragonBoat, BGSS10%SW, BG8868, BgoFErTaSchInA10, BgcLuBofErtA10, BGCuponation10, BGES456, 13f142, BGHONEY2110
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – 12x Xiaomi Radical 0.4mm Swiss Gel Pen [EU] ($-3)
Price history and price alert
Check out price history chart (for all/most countries) for 12x Xiaomi Radical 0.4mm Swiss Gel Pen.
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)).