you are leaving out market demand.
when the NES came out originally, there weren't a lot of other options.
there where a few hackers who were playing 'leather goddesses of phobos' on their Comadore 64 but other than a very small selection of graphic games, it was mostly unheard of to have 'video games'
currently: the market is saturated. where as the 8 bit nintendo had no rival, the new nintendo Wii has:
X-box, X-box 360, Playstation, Playstation 2, playstation 3, 8 bit nintendo, 16 bit super nintendo, Nintendo 64, game cube, playstation portable, game boy, game boy advance, game boy advance SP, game boy DS, the sega genesis, any number of computer systems, laptops, cellphones, PDA's, Mr. .99Y 'tiger' lcd games, etc, etc, etc.
competition is the real price dropper.
a month ago, the I-phone was $200 more than it is now. why? technology hasn't changed that much in a month.
but the market representing phones that are also MP3 players and internet devices and cameras has certainly stepped up their game.
-RuskiFace the Pirate