General Backup Problem: 2 or more CD game on 1 DVD

[Nope]

@Nope:
Hi. Where do you get from all these bins & cues ?

Sorry, but I don't understand the question. Those are just the image files of the disks - if this is the question.

EDIT:
Well, it seems that this is the question indeed... SO:
You do not copy on the CD the content of the disks itself, but instead you make image files - no matter what popular format you use - either bins or imgs or so on. Then you can write those CD images on the DVD. And tipical image file is around 700 MB (it's bigger then the CD itself), so you can backup on one DVD 6+ disks.
When you wnat to install and oplay the game from the DVD, you just load the image file in a virtual CD Drive using a program like Daemon Tools or similar; then you install the game as normal, use crack and play.
Hope this helps... if this is the question, of course:-)