Capacity 480ML, Size 6.50x 6.50x 21.70 cm, Weight 250g, Color Black.
Basically copy coupon, view price history or create e-mail price alert. 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 code price check (UTC time):
Banggood
Banggood warehouse is located in China. One coupon is available. Cool!
Link: Banggood product page
1. ($30.46): BG10OFFAFF1
apply it 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): 502C6B, vipupgrade8, TTxBG10, BGM20cc, BGss8%hl, bgssaff9, AFfbG10, 0e7f33, BGHOMEG12, BGAFF10OFF, bGhOnEy10, BGdragonBoat, BGSS10%SW, bgshOOp10, BGHome15%, BGHOMEA15%, BgcLuBofErtA10, BGCuponation10, 13f142, BG10OFFAFF, BGwhielabel
(there’s a little possibility that old coupon will work)
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi Pinlo Vacuum Cup 480ml Black? There we go. The lowest price was: $22.18.
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)).