fund raising

Hello, I'm helping hands. I have a child who was diagnosed at 3y an 9 months, I started to notice things just after my child turned 2. My boy has just turn 9 an what a long way we have come. His school is our only support system and now he's older and asking question's on his condition which can be tricky to explain and understand, as an adult I find myself drowning in autism sometimes. Autism awareness day is fast approaching,  and I've had the go ahead from his school that I along with other fabulous mummy's helping can hold a fundraiser. I want as much money as possible to go back into the school for other newly diagnosed children, but I'm also trying to get autism merchandise that we can sell with  that money going back to the national autistic society. So I'm looking for help and idea's in a way to get merchandise for free.....help please...much appreciated