Well, I posed a question some time ago concerning the relative merits of the Kepler experiment of finding exoplanets capable of harboring life vs the attempt to find the source for the existence of the universe itself via the LHC.  I would say that, as of today, the results are in and the winner is:.......a tie!

It is a tie as both experiments have proven their worth from a scientific point of view.  We have found dozens of exoplanets capable of harboring life and we have found the Higgs boson which is the key particle that likely created the material universe. That means we now have proof why we exist in the first place and with that, I can sleep well at night.  Financially,  can these be called even?

Considering we will likely never visit these exoplanets as we do not have the technology or even understand the science  that is capable of doing that, I would say that the money used could easily have been spent in better ways.  In doing so, we would have likely created new companies, built more schools, more prisons and perhaps lowered our national debt.  However, these questions would never have been answered had we not spent this cash so, therefore, we will call it an investment in our imagined future.