I was looking for smart scale for last 2 days and I found that Xiaomi Scale is a decent one which I can experiment with because of low price. But the scale was not available in HK and hence people were selling it for HK 250-280.
One of the group buying website came up with offer HKD 250 yesterday and today Xiaomi introduced the scale for HKD 139... It looks like grey market in HK will be a short time story only. It wont survive for long as products are introduced faster than before.