If we take the Ferrari racing program for billionaires at one end of the spectrum, the other end might be this: drifting at Ebisu circuit in Fukushima, Japan, where the goals include getting your car as close to the wall as possible. As formuladave contends, you can't argue about who spends more money in racing, but you can contest who has more fun:

Kind of funny.. After last night's bit in Top Gear where Jeremy drives the track-day Lotus and doesn't really enjoy it I have to laugh at this.

I spent $7500 on my Formula Vee, enclosed Trailer and a whole heap of spares.
My race entry for a two-day event is $250.
I can pick up a set of used slicks for $150. Depending on the track I'll use one to two full sets a weekend.
Last time I bought fuel (100 octane Low Lead aviation fuel) it was about $3.50/gallon. I bring 5 gallons per day to an event.

I act as my own support staff. I prep the car myself, maintain it during the weekend and tow all on my own. I even have little tricks to get the race car into the trailer alone. I usually sleep in a tent and bring a small grill. I pack a case or two of beer and some frozen burgers.

After all that I probably have way more fun than Mr. Rich with his full Ferrari support staff.

You're going to have a whole lot more fun if you're driving a car matched to your skill level than to your wallet..

That and most of us normal guys can't afford a car much beyond our skill level. I just hope that I can work hard enough to afford to keep my wallet up to pace with my racing skill.. One small jump up in skill takes a lot of $ by a normal human's standards.