In reply to Beardyman:
Disneyland is very expensive. Check around for voucher codes. Also factor in the fact that you can not take your own food or drink in, and the food and drink is, naturally, over priced in the parks. Having said all that it is worth a visit, teenagers will be less than impressed.
Worth considering is Parc Asterix. If you shop at Tesco you can use vouchers to pay for entry. You are allowed to take your food and drink in, food in the park isn't too badly priced. Good for toddlers through to teens, also has a dolphinarium.