Aliexpress
There’re some similar items on Aliexpress in my database. There may be some other items though.
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More on Aliexpress… Here are coupons that you can use.
Latest coupon and price update (UTC):
Price history and price alert
Price history (for all/most countries) for Xiaomi Redmi 6 3/32GB Gray is here.
Price records source(s): Gearbest
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You can set price alert (for Banggood).