It seriously bemuses me that people even think to ask questions like these sometimes. the idea that scientist go into science for the money is just ... ludicrous. In NZ, at least if you're lucky, you can get a job as a scientist with a comfortable income. there's a few rich ones around but I seriously suspect you'll find that they're rich coincidently, rather than having set out to get rich by doing science. Personally, the only reason I can see for doing science is so that you can spend a life figuring out how interesting stuff works. Which is fun. Analogous to Matt Damon's defence of teachers actually.