Can't you be spending your time doing something more productive?
Consider that any successful experience in cloning anything adds to our knowledge base about cloning. By perfecting cloning, we can do a lot more than just bring back extinct species. We could, for example, grow entirely new organs cloned from your body to replace damaged or failing ones, organs that could be transplanted into you without fear of tissue rejection. Further, the practice of being able to reliably modify cells at the genetic level can lead to all sorts of other benefits in medicine, biology, and even far-flung fields as nanotechnology when you consider the scale you have to work in.
The whole "can't you spend your time/money better" argument is pretty short-sighted when you consider the enormous ancillary benefits. It's like saying why bother going to the moon when you can spend money on Earth. But without that impetus, we might not have the very computers and Internet you're currently using to read this post, or lasers to correct your vision, or lightweight, strong materials used to make the planes you fly on, or the fuel cells used to power zero-emission vehicles, or...you get the idea.
Stop thinking in checkers. Think chess. It's not the current move that matters; it's the move you make three moves from now that wins the game.