Been to hongkong 2x this year and coming back!!! i fell in love with the place! Yup saw milan station and italy station in causeway bay (my fave area!) and mongkok as well. hmm... prices depend on the bag and its condition.. there are some brand new ones too. brand new ones are 20%-25% off lower than retail while the second hand ones go lower of course.
Are you sure the retail one is authentic?