Several of the roads on the AA route planner are subject to tolls. Calais to Paris (A26-A1) is operated by SANEF,
http://www.sanef.com/en/index.jsp and the toll is EUR18.50. Paris to Bourges (A10-A71 North) is operated by Cofiroute
http://www.cofiroute.fr/ and the toll is EUR19.10. Bourges to Clermont (A71 south) is operated by Paris-Rhin-Rhone,
http://www.parisrhinrhone.com/ - their toll calculator is "non disponsible", last time I did the journey it was about EUR11.00. Clermont to Beziers (A75) is toll-free except for the Millau Bridge (EUR6.50 - it saves you nearly an hour). Beziers to Perpignan (A9) is operated by Autoroutes Du Sud,
http://www.asf.fr/control/index.aspx?alias=hom e and the toll is EUR7.00.
Hope this helps - my parents live in Perpignan, we used to drive down a lot until Ryanair started flying to Girona from our local airport, that saved enough money for a hire car!!!