Spanish Toll Roads

As Simon says above you can take the national route from the border near La Junquera as far as the jct with the C95 just south of girona airport.You have the choice of the coast motorway to Barcelona or the AP both of which have tolls but are better than the national road alternative.After paying at Granollers you travel around Barcelona and pick up the route to Zaragoza via Lleida and Igualada which I believe is toll free and dualled.after Lleida/Fraga i think you can use the national road but it can be a drag depending on circumstances.I’m not sure on the toll cost but it is easy to google it to find out.