3x Xiaomi 0.5mm Ink Gel Metal Pen Refill (Banggood, Aliexpress: Writing thickness: 0.5mm, 3PCS per pack, Premec Switzerland (the best price with coupon)).
Check coupons or create price alert down below. You probably want to know what is the 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 coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. Coupons for 3x Xiaomi 0.5mm Ink Gel Metal Pen Refill? Nope, there’re no coupons in Banggood.
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/feV
Old coupons (from the oldest to the newest): e2bcea, TTxBG10
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Here is price history (for all/most countries) for 3x Xiaomi 0.5mm Ink Gel Metal Pen Refill. The lowest price was: $1.69.
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)).