It is cheaper for me to drive there, £55 for the frequent traveler fare each way and very little tolls as I will not use a motorway except to avoid Boulogne , Rouen and other impediments along the route which are not worth going through. Same back.. It might almost be worth getting a frequent traveler on the tunnel and only using a couple,, I get three and share the other two returns. Got two left until March but have a Spain coming for new year. then a little trip later on.