The “razors and razor blade” analogy is always the first to be employed when analysts — or technology reporters — begin their discussions of the copier/printer business. If you’re HP or Xerox, you sell the machine once, but you really make your money supplying customers with ink cartridges, toner and other supplies during the life of that machine. That’s why the new ColorQube 9200 office printer, announced Thursday by Xerox, could be a significant development in the industry.