The answer to that question is actually very complicated. If I'm billing it out, a lot. At the other end of the scale, there are thing I'll do for friends for free that I would refuse to accept as paying work because it's too tedious and unpleasant and/or I know the client would be a PITA. And I've done a lot of volunteer work, notably for a Bay Area performance art group, for which I not only wasn't paid, but I had to cover my own expenses, including travel. In other words, if I find something incredible enough to work on, I'll pay to do it.
I do R+D and startups, so I'm wired to accept varying likelihoods of success - or failure. I don't as a rule undertake something that has a high probability of failure, but again, there can be mitigating factors that make it acceptably attractive, like the people I get to work with and what we might learn along the way. This is sort of in that group. I know the odds of "success" are poor, but as we seem to have learned so far in this conversation, there may well be zero extant data points, and the idea of gathering the first is kind of attractive to me.
I get that many here, and you in particular, may find this a bu!!sh!t argument - I understand completely. And (esp. now that it's almost summer) I've got a lot of important stuff on my plate, so I'm not in a big rush to do this. Just keeping it in mind should the the opportunity, inclination, and a little extra time coincide.