Jonathan Caouette ransacked his home movies and edited them into a documentary costing, famously, $218. That's an impressive cost-to-gross ratio for a film that made over $1 million worldwide. Less impressive when you factor in $400,000 post-production and marketing costs, but that's true of most of these films.
Secrets Of Its Success:
The pure novelty factor of a film that highlighted the sophistication of home retail filmmaking kit. As a narrative, Caouette's story of sexuality and mental illness is, shall we say, niche.