Money, well
I have NO idea what it would be. But I can tell you it will not be as much as you spend on the bike ! And what do you do, well, join the AMA ( I think it's ama.com - it stands for American Motorcycle Association ) first, get into club racing (which means you go to a school to get a license) , set up a racing bike and go racing. Your local track can help you get started. Just look around for track days and go. Ask ALOT of questions and you'll get your answers.