Go down and check coupons out. Remember to check price history if it is available. Best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Insulation Length 6 Hours 84 Proof above, Brand XIAOMI, Capacity 41 Ml (Inclusive)-500Ml (Inclusive), Certification CIQ, Feature Eco-Friendly, Production Thermos, Material 316 Stainless Steel, Thermal Insulation Performance 6-12 hours, Color White Black
Banggood
Banggood warehouse is located in Europe 
. I don’t really know if this price is reasonable, coz there’s no price history in my DB.
Link: Banggood product page
1. ($22.99): BGJAFR313
2. ($23.99): BGDEFO313
3. ($28.79): BGAFF10OFF
apply it 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/5cd
Old coupons (from the oldest to the newest): BGDESE313, BgcLuBofErtA10
(there’s a little possibility that old coupon will work)
Price history and price alert
Not enough data to show price history chart… $22.99 is the only recorded price. It was not cheaper than that since we have saved it in DB.
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)).