" How often during the week do you use this stuff? " Virtually every day, occasionally twice a day. "How much can be prepped in advance?" I suppose that some things could be cut up in advance but a lot of my activity is for salads which, IMO, are better freshly chopped. Things that I prepare most often are onions, garlic, celery, bell pepper, tomatoes, cucumber, lettuce, carrots and potatoes. However, there are a lot of other things, herbs, nuts, ginger, zest, etc., depending on the meal that I'm preparing. "Is it things that will last 3, 5, 7,10 days?" Again IMO, very few things would remain viable/usable for more than a day or two.