We've just booked winter rallies and the tunnel with the CCC. The tunnel was about £35 cheaper with the club than direct through Eurotunnel. The main rally is something like €9 a night as we're staying more than 30 nights.
It's correct that the booking fee of £75 is waived if you book the crossings as well but, if you go independently, you can't join in the rally events, which are dirt cheap and great fun. It's not just a matter of taking your chair over, there are trips and rally-only meals and parties and all sorts.
You also get the ACSI book slightly cheaper and you don't pay the £5.50 for the Camping card.
The CAMC use a lot of the same sites but don't do the rallies so they're probably more expensive in the long run.
Nora
Don't forget to leave a review of the French and other European campsites you have visited!
I did three sites that had CCC rallies on them at the same time, on two of the three I was paying less per night using my ACSI card and on the third site it was 50 cents more. I use Dover Calais ferry which is cheap as chips anyway, I like the flexibility of the ticket with four hours leeway either side, don't know if CCC do that ticket. On Almafra the club had about 60 pitches, all were full, on Marjal Costa the club had a piece of the site to themselves, all 7 units! Would rather plan my own trip