The only question is who is fronting the money for this. And even then if it is US tax payers it is only a small fraction of money for each person in the US. There are over 300 million people in the US. This means that each person is paying $1 for the initive. That is not too high a price for something so amazing.
234 stars have been observed intermittently giving off bizarre strobe like signals, leading some scientists to believe that this might be a method of extra-terrestrial life attempting to contact human beings. If their hypothesis are correct, the initiative charged with the investigation will have made the biggest scientific breakthrough of all time - the discovery of intelligent extra-terrestrial life. $100 million is a small price to pay for such a breakthrough.
It is easy to say that something is a waste if money when you solely look at the monetary number. When you look at this as what the possibility of discovery means. This would be a monumental discovery that would answer age old questions about alien life. Most discoveries seemed like ludicrous ideas before they were executed.
No, allocating money to listen to signals coming from a particular star is important. Our human race must continue to grow, learn, and evolve. We can do so more effectively when we learn more about the planets and stars around us. If there are other civilizations out there, and I believe there are, then we need to make the effort to make contact.