Greetings!!

Honestly if you consider it depends on your wish to study any of these subjects and become successful in any of these fields. If you wish to become a space scientist but taking up MBBS thinking about Pay scale then it would take long years to succeed. However Aerospace is really a Fascinating field for those who dream to fly, now if you consider the general payscale of a Doctor it can range from 10-50 LPA also. For a Space Scientist also it is applicable, however in every field you need to gather profound knowledge and experience.

Good luck !!