I'm running Ubuntu 13.10 32bit with Gnome 3.8 but am missing the Ubuntu Software Center. I tried to install it via terminal:

$ sudo apt-get install software-center

But that tells me that dependencies are not met

The following packages have unmet dependencies:
    software-center : Depends: gir1.2-webkit-3.0 but it is not going to be installed

gir1.2-webkit-3.0 depends on gir1.2-javascriptcoregtk-3.0 of version 1.10.2-0ubuntu2. But that package is only available as version 2.0.4-2~ubuntu13.04.

I am missing the Ubuntu Software Center as well as the Update Manager and the packages update-notifyer and ubuntu-release-upgrader-gtk.

How can I install the packages with correct dependencies?

Edit:

Output of apt-cache policy gir1.2-javascriptcoregtk-3.0:

gir1.2-javascriptcoregtk-3.0:
  Installed: 2.0.4-2~ubuntu13.04.1
  Candidate: 2.0.4-2~ubuntu13.04.1
  Version table:
 *** 2.0.4-2~ubuntu13.04.1 0
    100 /var/lib/dpkg/status
     1.10.2-0ubuntu2 0
    500 http://de.archive.ubuntu.com/ubuntu/ saucy/main i386 Packages

My sources.list:

deb http://de.archive.ubuntu.com/ubuntu/ saucy main restricted universe multiverse
deb http://de.archive.ubuntu.com/ubuntu/ saucy-security main restricted universe multiverse
deb http://de.archive.ubuntu.com/ubuntu/ saucy-updates main restricted universe multiverse
deb http://archive.canonical.com/ubuntu saucy partner
deb http://extras.ubuntu.com/ubuntu saucy main

# spotify
deb http://repository.spotify.com stable non-free

Spotify I added myself.