For me it totally depends on what type of tea I am drinking, or tea ceremony I am performing. When drinking Chinese tea, I use Chinese tea ware, for Korean Tea, I use Korean tea ware, and for Japanese tea, I use Japanese Tea ware. Some teas I like to use glass to watch the leaves dance, while others, I want it to have a white interior to see the color of the tea liquor. I have some cups which are ideal for really smelling the teas aromas, and others which are large for when I am working on a project and do not wish to be constantly stopping to brew more. When doing the Song Dynasty tea ceremony, I use a different shape altogether, so other than price, I choose all the above.