Very Simple Question...

I getting ready to start my first build, and in doing my research, I've found several places that highly recommend using a case/mobo speaker. I've got a couple of questions.

First, is it really necessary to used a speaker? I'm not so cheap to avoid buying a part that's only a couple of bucks, but I don't want to be waiting for a part that won't do anything.

Second, is there any use for it once I've gotten past the initial setup? If all its going to do is beep everytime I start the computer up, I'd rather not have it.

Third, how can you tell if the case/mobo already has a speaker? I'm using an Antec 902 and an ASUS M4A79XTD EVO. I know the case doesn't have one, but haven't found anything about the board.

Thanks for the help.