I believe that the PhD is worth it, well was for me. Jump in economic opportunity when I went from a MSc to a PhD is the biochemistry field.
Define your goal, then build a strategy to get there, an informed strategy. Within that strategy, the PhD might be helpful in getting to the goal faster or completing the goal in a more robust way.
I did mine while working full time and being married with kids, was tough and did not sleep much as I also was a GA for two classes (kept my university costs down as Big Ach or someone mentioned).
dknole