I have a texture backup folder. I keep the main textures there if I modify them. This way I just switch from original to modified depending on my needs.

As for runtimes, about 50Gb. I am in the middle of burning them all on DVD's to work on my PC. So I can't show the real numbers.

Some of those big file are Cr2's to be able to work with MorphManager and other apps that don't read Crz's. You would be surprised at how much space you would save convering the Cr2 to Crz.