So I've been communicating with this small company that approached me funded by a nonprofit organization, and they seem to want to pay me appropriately, however they want to pay me every two months upon completion of certain phases of development. They want me to design, code, calibrate, and test a device that reads signals from organic cells. I'm okay with this for now, however they're asking for me to sign an NDA and instead of being told how much they can pay me, they're asking me how I'd like to be compensated for each phase.
Again, each phase is a two month period. I have no idea what kind of pay to ask for, and I could really use some advice on this!