AWfC - I wonder if you talked with the local paper's features editor about doing an article about you and your haunt - show them your pics from last year, tell them how many TOTers you get, and have the article go into WHY you do it every year. If you get a positive response (and you probably will - editors are ALWAYS looking for Halloween-themed or related stories that time of year) you could then approach a sponsor with the opportunity of having their store mentioned in the story, along the lines of "Seeing the extend that (Mr.and Mrs. AWfC) go to bring magic to the kids on Halloween ,(your sponsor store) decided to help out and donate goodies to the hundreds of kids who show up to enjoy the Halloween display."
It's worth a shot...