How much to knock through 2 rooms.

I would like to know the rough cost for the following work. We want to create a kitchen diner by: 1) Removing a stud wall and making good (non load bearing). The wall is approx 2 metres in length. 2) Removal of coving in one room (5m x 3m) making good and skimming over ceiling in both rooms (total space will become approx 7m long x 3m wide). The house is relatively new so ceilings are low and rated will not contain aspestos. 3) Relocate the door to the understairs cupboard by moving it onto another (plasterboard) wall. 4) Partially brick up an external doorway which currently houses a sliding glass door and replace with a single door (either wood or upvc). We would like a rough idea of cost so we can decide the extent of the changes we can make. I have had a number of builders around to quote but none have come back to me.