It's not just an investment though, the OP has committed to doing some serious marketing, let's say at least equal to the amount of work that the dev co-founder puts in to create the product in the first place.
From what I read, he was committing $3k towards marketing and gathering users, but did not specify how much work he'd personally do. Just want to make sure any people new to this ask the right questions up front, I'm not implying that hmexx is trying to screw anyone