Knowledge is a need

Before 1492 Columbus idea of the roundness of the Globe was rejected and some (Galileo) even went into prison for sponsoring it.
Most of the existing countries believed it was a waste of money to send Columbus on a wild chase to reach the East going West.
Yet the discovery of the New World made a big difference to the Old one (and may be that was one of the reasons nobody wanted to reach the East going West, because that meant what actually happened, that the Mediterranean world lost its commercial and financial power).
We are at the same crossing now: spreading out into space will have an even greater effect; it will completely change the future of the human race and maybe determine whether we have any future at all.
It won't have an immediate change in our lifestyle on earth, but it will give us a new perspective of our problems and may be solve them.
It is going to be a long term dicovery, meaning we will reach the goal of a base into space in nothing less than 50 years and it won't be cheap of course.
Many would object that money would be better spent in solving the problems of our earth, but in my opinion it would cause great advances in technology, as it did in the past, like the first large-scale integrated circuits which are the basis of all modern computers.
It would also mean a change in interest in Science and technology.
We live in a society that is increasingly governed by science and technology, yet fewer and fewer know anything about science.
Since Ulisse's times there was and will always be the need for humans to know where we live and where we came from.