A couple more things:

An option that would allow me to scan a CD and obtain the peak volume levels of each track would work too. I wouldn't mind putting in 300 CDs if it only took a minute to scan the CD.

I also realize that a lot of newer CDs are already normalized, so I probably wouldn't have to go through 150 or so, since they're decently new and are popular music. I'm really only running into the issue now, when I'm ripping all my classical-type music.