It's kind of sad that startups are a game for people who have a long personal runway (combination of savings and cheap lifestyle, usually), but that's the reality.
No investor is going to be excited to see their money put to work by paying down student loan bills, though at a certain level you can often swing a 50-70k salary. As I understand it, get big revenue or a big Series B round, and you can generally lobby successfully for a non-insulting salary.