This is very normal. As fimo stated, the issue is less Narita cheap but more about reliability and trust.

Most Chinese shoppers will take advantage of travel (biz or holiday), to get gifts, household products and even milk powder for themselves or family/friends.

When it comes to branded goods for the upmarket shoppers, it can become even more apparent. I've witness a lady in Burberry duty free at CPH, who promptly bought one each of every bag from the latest collection. I thought I was going to miss out on my W's anniversary present.