Who can compare the [复制链接]

hi,
  Since I am in USA so I can not input Chinese.
  I have a question on Sony's GR, please visit http://www.sonystyle.com/vaio/gr/index.shtml, then you will find that the price of 150 and 170 are higher than 250, but the difference in quality is very small and I even think that 250 is better than 150 and 170.
  Why the price of 150, 170 are higher than 250?
  Thanks!