Availability is one aspect. Availability with buyer protection according to his country's and region's laws is the other aspect. Aliexpress may provide availability but, on its "German" webpage, does not comply by German law (a legal site notice with address and contact data is missing). In Aliexpress's terms, there is an implicit conflict between the laws of Hongkong and EU / German laws and jurisdictions. 15 days return sounds reasonable until one thinks about it in practice: how long does it take to return a parcel through customs to Hong Kong? It is risky to buy expensive goods overseas!