If the ultimate motivation is to earn money, then PHD is never worth it. It's for people who want to change the world by doing major breakthroughs in their respective fields and make the highest impact towards the society. And about scholarship, it depends on your capability, profile, cg, researches you've done during your under and post grad, location, institution, subject and many more. Go through yt, google, fb groups to get more knowledge about scholarships. You need to do research about scholarships. After all, it's RESEARCH you are going to do when you'll become a PHD student.