We went Dover to Calais, ?100 for tickets, the drive down to Le Mans is about 6-7 hours,the tickets are 70 euros for the weekend pass to the race, not sure about the camping costs, very cheap though.
We went down on the wednesday and stayed till monday becaused its the best way to experience the whole race, build up etc and seeing all the amazing cars that are there!! Was such a good time, we are booking for next year this week!!
Mike