Nope, there is no average and every school is different. Your best bet is to wait until the order is turned in and work off it. I do a yearly fundraiser with our local HS but we do it a little differently. They buy the candles outright from me so they can sell them on the spot. They just started today and ordered 12 cases to start. When those are sold they order more, they love doing it this way and so do I, no forms to print! Since my business is wholesale I always have stock made up so turnaround time is just a day or two when they reorder. No I don't get my money upfront, i turn in an invoice when I deliver and my check is mailed, usually around 2 weeks but this isn't a big deal, when you deal with schools invoicing is pretty standard.