I saw this auction link in Yahoo. You can ask them and check if that is suitable for kids.
If your kid is older enough, can try to join some children course in Alliance Française de Hong Kong. The course website is : http://www.alliancefrancaise.com.hk/en/lescours/course_content/workshops_children.pdf
Or you can buy a French/English dictionary to learn the french vocab first.
I do tailor shopping for french books from France to HK, but if they sell so cheap, I can't bid. But of course, I notice that their books are usually from UK not from France.