I don't want to write an asking price here, and honestly I don't know how to valuate an open-source project. But I could have been working for Google as a staff engineer and enjoy a decent salary instead of doing this project, so, well...
Hmm, I thought you were at Google. Did you leave? Regardless of whether you're at Google I think you deserve fair compensation. But IMO the value of mold isn't limited by your opportunity cost of a salary. It's state of the art linker and someone like Apple/FB/etc can and should be willing to compensate you.
I left Google last year. And you are right; mold (or anything that I create) should not be valued at my opportunity cost but instead at its intrinsic value.
