ubun2

They might be cashing in because download 0.5GB is most countries not possible. It is hard to answer what they could put inside those CD's.

Instead the best way is one of the following:

If you have faster connection, you can download directly from http://www.ubuntu.com/download

or

you can order CD directly from http://shop.canonical.com/index.php?currency=USD&cPath=17 which is ubuntu's official shopping site.