It's actually not a bad idea (and a cheap one too) to "back up" DVDs onto 2 discs. 8x DVD+Rs can be had for $20 for a 50 pack. Just get the right program and you can trim out all the fat (menus, special features, subtitles, director's commentary) and you'll only need to slightly compress the DVD to the point at which our eyes can't discern any difference from the original.