No.
£24 admission is £20 + VAT. So a 500 crowd at £20 is £10k.
On average there are 100 points in a meeting, so just £100 per point would wipe out that £10k, without even taking into account the riders' travel expenses and flights and tyres.
Then there's signing on fees, stadium rent, insurance, medical cover, meeting fees, referee fee, track preparation, other staff costs, utilities, etc etc.
You wouldn't get far on the gate money of 500 people