Do you mean the Sony DSC-F717 or the Sony DSC-F707, as the DSC-F707 has been discontinued for quite a while.

Once you get to that price level you are not paying extra money to get extra pixels, you are paying for a camera with a bigger and better lense. In my experience having a good big lense is very important.

When I bought my current digital camera (an Olympus D-600L) 5 years ago I bought the camera with the largest/best lense I could find. I have not regretted my decision to spend the extra. Despite the fact that it only has 1.3 mega pixels, it is still taking pictures on par with the average consumer digital cameras available now.

If I had spent a couple of hundred $100 less I would probably have had to replace it a couple of years ago.

P.S. I'm hoping to be upgrading to a Canon 10D + a 28-135mm image stabilized lense next month. If I can convince myself that spending $2500 on a camera is a sensible thing to do...