In a post by Twitter user Hoonable, we see an image of the racing fuel pre-order for the IMSA race team. It's not cheap, costing as much as $14.60 a gallon.
"For those that are curious, this is what the order form and prices for the racing fuel look like.
IMSA100E10 used in the TCR cars is $12.90 per gallon ($696.60/drum)
IMSA E20 used in the DPI cars is $14.60 per gallon ($788.40/drum)"
And these don't last very long, either. When they're racing, they're burning fuel as tremendous rates.
So take the millions for making the race car, the six digit entry fees, and the high price of gas, and combine that with the cost of research and development, staff wages, and everything else. No wonder it costs automakers three to five million just for a single race.