UPDATE:

It was brought to my attention that the Sega Dreamcast is more aptly considered a competitor to the Playstation 2, Xbox, and Gamecube consoles, rather than the previous generation. All three graphs have been updated to reflect this change.

Here is a graph of the prices of some of the main (and not so main) consoles dating back to 1986. The consoles have been put into four generation groups. Some of these groupings can be questioned because of close time proximity, or varying competition, but this is a fairly accepted grouping.

This is a graph of the relative market share percentages of the same consoles from above. The market shares are confined into the groups, so the data does not become skewed by varying sales between console generations.

This final graph shows the average market share of consoles at specific prices. The prices and market share percentages were taken from the same consoles used before. As you can see, the consoles priced at $190, $200, and $300 have been the top performers, by far. There isn't a truly solid trend, as some consoles below $200 and from $200-300 failed miserably, but the statistics are pretty revealing nevertheless. The consoles that were $400 and above failed. These consoles had stellar graphics and innovation, but they were not viable competitors because of their cost. Gaming consoles need to have a high quality to price ratio to sell well. This is why several consoles long ago that were fairly inexpensive failed horribly... they were garbage. And while the expensive consoles may have had a higher quality, it wasn't enough to counteract the extreme price. This seems is the setup for the Playstation 3. Sure the PS3 packs alot of features and high quality graphics, although even its power has come into question, but will it be good enough to justify $499/599?  Will the trend continue? Or will Blu-ray, Sony's PS and PS2 market shares, high definition graphics and games save the PS3? Only time will tell.