Sounds like a good deal, if you are the Rolling Stones. If nobody has ever heard of you, it could be a hard sell, from a business venture perspective. Somewhere in between the Stones and obscure, some market research would be required. If there is no proven market, then I would say to you the same thing I say to my customers who come to me with a great, vertical-market software idea; if you believe in yourself (or your product), and it's marketability, then put your money where your mouth is, and we'll write a contract that says you get all of the proceeds until you have recapped your investment, then we'll split the profits as set forth in our contract.
That's my business opinion. If I thought I'd have a lot of fun making your movie and I didn't need the money, I may take a different approach. Please understand that there are lots of people out there who have "great ideas", in markets with which they have intimate experience. Many of those people have no marketing/business savvy, and I am not confident that I can make money on their idea. It only seems fair that if they believe the idea is marketable, then they should put down some of their hard earned cash, up front, to give me confidence in their judgment. If they tell me that they have no money, that fact, in itself, gives me some idea of their previous experience in business.
Having said all that, let me add that my perspective is much different than a film maker who is trying to get his name out there and may leap at a chance to work with a group of talented, motivated people on a project that could look really good on his resume'. I write commercial software and produce commercial video projects, so I am not aspiring to make a big name for myself in the movie industry. I'm just giving you my perspective on your project (with what little I know about it).
