The hexagram is determined by tossing three coins, three times by the inquirer. The I-Ching is based upon an entire philosophy which is the unified and cyclical universe, the future develops according to fixed laws and numbers. This seems quite harmless, and passes off as more of a game instead of what the person is really using it for. One needs to know how to interpret the meanings of the patterns. More of seeing the answer then trying to figure the answer out.
Crystal balls are more expensive the bigger they get.
As with any tool, proper caution and handling should be seen to when using, however more precaution needs to be placed into the tool, the crystal ball. Scratches and flaws will affect useage. Similar to the crystal gazing. With the scrying, you are making your tool, which then in turn makes it more powerful,in my opinion to your hands. Again specific answers and situations can be seen.