The Sacrifice

So everyone knows that the Sacrifice is coming out on Tuesday. I read on the Left 4 Dead blog that it's 540 Microsoft points for each package. I know there is the new map The Sacrifice and there's No Mercy for Left 4 Dead 2...but when they said package, do they mean that it's 540 MP for each map? Or is it 540 per package of the two maps? I know it said it's coming out for Left 4 Dead 1 and 2...but is there a difference between the DLC's for both games? They really didn't answer any of the questions on the website. This is what they posted on the blog:

“The Sacrifice” campaign for Left 4 Dead 1 is coming!
“The Sacrifice” and “No Mercy” campaigns for Left 4 Dead 2 are coming!

So if you download The Sacrifice on Left 4 Dead 1, you won't get No Mercy with Left 4 Dead 2 infected, weapons, ect...? Why would anyone want to download it? Why pay the same amount for two campaign that you would for 1? But, anyways. I'm going to download it and play it as soon as it comes out. I'm going to run through it with my boyfriend, and upload the footage to YouTube that night. Then, after that's all said and done, I'm going to get started on Achievement videos. I'm going to make a whole new set of videos called "Got Achievements?" that will be a collection of How-To guides for achievements in the games I play. It's not going to be as broad as RoosterTeeth or anything, but it will hopefully help some of my viewers. :)
I found a list of Achievements for The Sacrifice:
Supreme Sacrifice- Complete "The Sacrifice"
Kill Bill- Have Bill sacrifice himself for the team.
Chaos Generator- Have all 3 generators running at once in "The Sacrifice" finale.
Sacrifizzle- As a Special Infected, incap someone who is trying to sacrifice themselves.
Barrel Rolled- Kill a Special Infected with an exploding barrel