Well speaking as last year's organiser, we lost over £500 on the race, so I don't think the odd pound to cover the costs (or minimise the loss) is very much to ask
You need to take lessons from the Trunce , charge £1.00 (£0.20 field fund) per race, run it 9 times in the year and have plenty money left to give to local charities.
Seriously though, not many places you can get so much fun for 4 hours for £11.