As I had notice both Bioshock, Eternal Sonata and others year old game had perform not so good during the recent release.

what is the main reason out there in the market?? I am just curious.

Most people usually already played the games, if they're true gamers that is.

Or maybe some people couldn't play them before because they were short on money at the time these games were released, but usually they have friends as well...! ;)

niche games generally don't have legs unless it bundled.

by the time the port comes unless its hidden gem it won't sell.

No matter how much you hype an old game it will never sell as good as the orignal.

Some advertising and old games will see a little boost in sales

 Resident Evil 4

Because people prefer the new ones: LBP , FarCry , Fallout , Fable , R2
how can ES and Bioshock sell?? the new releases are much more appealing

Basically, as soon as a 'hardcore' game has been out on the market for more than a week, the hardest of the hardcore have already played through it, beaten everything there is to beat, and sold it back to gamestop for $5 towards the next week's game. Gamestop will sell these games to the customers for 50$ (or 40$ on the wii), making a huge profit, and not contributing to the sales totals for the game at all.

As for recent ports, it's you lose out on the committed fanbase, and if a game has been out for 6 months and it's really good like Bioshock, you've probably played it quite a bit, even if you don't own a 360, assuming somebody in your peer-group owns one.

I don't know if there is a single answer for this ...

One thing I can think of is the release of a highly anticipated game generally generates a lot of word-of-mouth and (gaming) media interest which dramatically increases interest in a game, while the release of a year old port tends to be pretty anti-climatic.

Something I have noticed in myself that is (somewhat) related is that when I look at the value-priced games or used games of a fairly old platform I tend to see lots of games I always intended on playing but never got around to. I don't know what it is but if I haven't bought a game within 3 (or so) months I (generally) don't pick it up until I see it as a budget game.

          This ^^,

          throw in other titles like Gears 2, Left4Dead, Guitar Hero World Tour, Rock Band 2, WKC, Last Remnant, ect., it is tough on the pocket book and takes up a significant amount of time. Early next year you get others like KZ2, RE5, Halo Wars, SFIV......sheesh, its no wonder they dont sell as well!