There are a lotof  inside materials for your choice as below;

   Honeycomb paper is the cheapest material but alsogood quality

  Hollow chipboard & 50% solid wood & solidchipboard are the middle grade materil for your choices

         The door framecan be.........

                 fingerjoint solid wood withmdf veneer

                plywood with veneer

          Thearchitraves can be.......

                  plywood with mdfveneer

                 plywood with veneer

                  mdf with veneer

                    solid rawwood

         There aremany solid wood kinds for your choice too!