I race my bike, which is arguably one of the more expensive ways of enjoying this hobby. There are race fees, license fees, team fees, coaching/conditioning fees, travel to races,clothing, tegaderm, etc. That doesn't even count the multiple bikes for different disciplines.
But compared to racing boats, cars, motorcycles, or planes? Mere pennies. I bet some car guys spend more on a track weekend than I do all year racing my bike.