If your talking about L4D2 then all the content created by Valve is free.
You can't get The Passing on Left 4 Dead 1. It is only a DLC for Left 4 Dead 2.
Yes, in the co-op or single player campagin.
Depends on what you want, check the discriptions, ratings, and comments.
Most DLC for the Xbox is around 800 Microsoft points. Although I do think that PC users will be getting it for free
No they do not come in stores theirs a reason why they call it a dlc its for downloadable content you can get it on live on any game system
You can purchase The Sacrifice DLC for Left 4 Dead 2, which has you play as characters from the first game. Additionally, you can put character skins of the original characters onto the characters of Left 4 Dead 2 (Only in the PC version)
What u have to do is go to left 4 dead 2 and search for sacrifice and the passing and you have to buy the missions and if u don't want to then you have to get an account and play it online
You have the restart the game inorder for the DLC to work.
you will have to buy the uprising dlc you get mob of the dead + some mp maps you can also hack the dlc thru computer if you want to hack it search google for how to get upeising dlc free
No current download-able content on the Xbox Live Marketplace can be used in Dead Space 2 because it is not released and the developers/publishers do not have any plans to create DLC for this game.
as of 5/14/2013 Left 4 Dead 2 cost 29.99
Assuming you're including the DLC (As of 2013) No Mercy, Crash Course, Blood Harvest, Dead Centre, The Sacrifice, The Passing, Dark Carnival, Swamp Fever, Hard Rain, The Parish. (Campains not canon in the story line) Dead Air, Death Toll, Cold Stream. (Not Including L4D1 Crossover DLC) Dead Centre, The Passing, Dark Carnival, Swamp Fever, Hard Rain, The Parish. (No DLC) Dead Centre, Dark Carnival, Swamp Fever, Hard Rain, The Parish.