I bought a lovely 4.5kw stove from an ebay seller for £250 a couple of months ago. Our fitter said he'd never fitted a cheaper stove but it looks great, knocking out disgusting stone clad 70s monstrosity,fitting a solid slate hearth, lining and sorting chimney, replastering chimney breast and fitting stove cost £1600. Im in Brighton.
Our chimney specialist charged us £1100 to take out old gas fire and reline flue and fit the new wood burner. He also fitted the new hearth and put in fireboard in too. I'm in the NW Our woodburner cost £299 from fireplace warehouse