Hi mate, i can give you a few pointers, in my experience dover/calais is the most cost effective route £35 p&o then follow the route through france, rouen-evreux-dreux-chartres-orleans-clermont ferrand-over millau bridge, to a9 narbonne/ perpignan....espana. i have done this route for many years [ i am a truck driver] its the cheapest for tolls and its worth it to go over the 2nd highest bridge in the world.