While it does seem odd to box content that is downloadable only via Xbox Live they've gone and done it anyway- take that conformists! It's priced at $19.99 for February 17th.
The reason for packaging the DLC is because it'll "include a 2 sided poster" aside from the unique code to grab the ones and zeros off the net. This is only available on the Xbox 360.
"Making these episodes has enabled us to expand the narrative and the experience of interacting with a game world in really innovative ways," said Rockstar's Sam Houser.