OK, we've had a few scrapbook crops over the last couple of years.
Number one, if you have it at the school, check to make sure there is no janitor fees involved. The first year I took it over, the district imposed a fee after the event of course, and a 12 hour crop with janitor fees of 45.00 per hour, well, you do the math, there went my big profit. The next year we had it at a banquet hall off school grounds, a good place with good food, but I had to gaurantee and pay for 50 people... well I only had 31 paying croppers, again, not a good profit. And remember, I was charging 35.00 per person to crop, we had 50/50's and raffles throughout the day. This year I switch to 2 5 hour crops at the school on a Friday night- it started at 5pm-- ended at 10pm. I served pizza and salad, plus drinks and desserts. I charged only 10.00 per person... You could charge 15.00 per. I had 50/50's and raffles during this time as well. This went great! Everyone had a great time, it wasn't high priced, so I had a good turn out. Next year that's all I'll be doing. When you have a crop, don't forget the chocolate- croppers crave that little pick me up half way through. And as far as donations go, if you start early and go on line searching the scrapbook supply companies... you can find quite a few that will donate something- most need 60-90 days notice, but it's worth it... you can get some great prizes, same goes for desserts- hit up your local bakeries, even doughnut stores-- get as much donated as possible.
Good luck!