I'd like to make a percentage bid: 10% flat rate for everything raised over the dollar amount you have when I take on the project plus and additional 2.5% for dollar amounts over each of your stretch goals (e.g. 12.5% for anything over $125,000 up to $150,000).
I would like to speak with you before taking the project, though, to get some additional information about the project itself and your availability for interviews and the like.