The description states "Foto Nr. 6 zeigt artverwandte Saint Louis Briefbeschwerer mit eingeschmolzenen Blüten und Blattwerk (nur Demonstration!)" .... Image 6 shows related SL paperweights with flowers and leaves molten in (for demonstration only).
In other words (my personal interpretation) - the seller is aware of the fact this is NOT Saint Louis. On the other hand, the wording implies that the seller may not be very knowledgeable about paperweights.
China is certainly a plausible origin - but I guess it could have come from another part of the world as well.
Have contacted the seller?