landarc hit it pretty good with his figures.
I just did a 400 plate catering job and used 50 pounds of cabbage (whole heads). We got about 45 pounds of shredded (about 10% loss to damaged outside leaves and cores). We served up about 3.5 oz servings (4 oz seemed a bit large).
My dressing is VERY simple and yet quite creamy and delicious:
1 part Mayo (Duke's)
1/2 part sugar
1/3 part vinegar (apple cider vinegar)
I.e., 1 cup or 1 gallon or whatever.
I mixed up 3 gallons mayo, the equivalent of 1 1/2 gallons sugar, and 1 gallon vinegar with a healthy handful of pepper and it seemed to be just the right amount. Let the cabbage sit in the mix overnight and toss the next day. It looks too dry the first day, but just right the second day.
CMJ - KCBS
CBJ - MBN, NCBS, NCPC
OBJ - BBQCritic.com
CTC - KCBS
Pitmaster and chef - "4 Lil' Pigs" Competition BBQ Team
Author of "A 'Q' Review"
Lang Hybrid Smoker, BDS, Holland "Epic"