They don't make this easy, do they?
I did some research (thank heavens for the Internet) and here's what I found...
No reference to a $10,000 amount, but definitely a two-fundraiser rule. It sounded contradictory to me. One place it said if you hold more than 2 sales fundraisers, all the fundraisers - including the first two - were taxable. But in the same document, it says if you hold more than two, you must pay sales tax on items purchased on subsequent ones.
First - you have to figure out what is taxable in your state. Sales of "things" (t-shirts, school supplies) would be. Candy is not. Admission to events is not. Foods prepared by volunteers are not taxable. (i.e., spaghetti dinner - not taxable, re-selling pizza - taxable.) Donations would not be taxable.
So you only need worry about the fundraisers that ARE taxable. Worst case, some of the fundraisers are taxable. All that means is that you have to pay 6-7% (plus local tax) sales tax each year. It's sad to lose any part of the funds, but it's an expense just like any other.
Call your Department of Revenue for more info (615) 253-0600 or (800) 342-1003 and I've listed a couple publications links below:
Tenn. Sales & Tax Guide (Dec. 2004)
tennessee.gov/revenue/taxguides/salesuse2004.pdf
Dept. of Rev Notice on Sales Tax Exemption
July 1, 2003
tennessee.gov/revenue/notices/sales/nonprofit03-22.pdf
Note - also finds out where the school fits. I think they are subject to the "two fundraiser rule" also. But are they holding any? Does that mean you could do 4 per year betweent the two orgs. Also think creatively. If you raise admission and provide "complimentary" pizza and drinks, you really aren't selling food, are you?
Report back and let us know how it works out.