By this, do you mean upgrading from digital download to the game on a CD? Because if so...
You can get each Bone game on a "Director's Cut" CD, but I don't think it works as an upgrade like the other games. They cost more than the downloads on their own (probably due to some extra things on the CD, though I'm not certain as I only have the downloads) and it looks like you have to pay the full price for them, whether you have the games as downloads or not.
So basically there are CD versions available, but it looks like you don't get them for cheaper if you already own the downloads. I hope I've given you the info you were looking for!
