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Click here… to search for Xiaomi VIOMI V2 Robot Vacuum Cleaner on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in Hong Kong.
Link: Banggood product page
Coupon (319.99 USD): BGXVMB
Coupon (371.99 USD): aff7off
Coupon (371.99 USD): bGpAnDacHeCk
(CouponsFromChina.com tip: paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGHA5FF, PICODICOM, BGVM001, BGVM04, a8cfc9, BGVIM07, BGSV2B7, BGV2BOT7, BG925b3c, BGSUV2, BGRB08VI, BGXMVM339, BGXMVM, BG13thplviomi, BGVI209, BGVMV2, BGVMV29, BGVM2X, bgchinafest, BGVMXM2, BGVM2RB, BGVM2H, BGXVM2, BGXVCRA, BGVMV2R, BGV2RBD
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi VIOMI V2 Robot Vacuum Cleaner.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).