That must be very frustrating. Maybe I should seriously consider opening such a shop. Seems good business idea.
However, I’d like to point out that a good gaiwan is well described in teaguardian.com, it does not have to be translucent, but the shape and thickness distribution must be right. Such good stuff can actually be quite affordable in many asian countries, because China makes a lot such things very well but cheap. Excellent handmade gaiwans are rare anywhere and are expensive. I bought some expensive but not so good ones in bad shops before too, so I always buy mine only from real shops — there are no such good shops nearby, I’ll have to travel by train for almost 4 hours to get to one!
