Exhaust for Fabia 1.4 16v (2000)

The current back box on my Fabia 1.4 16v (2000) has corroded and split though surprisingly it is quiet although encountering potholes and speedbumps now causes a knocking or banging. I suspect it is a mild steel cover for the actual functional part of the exhaust backbox.

Does anyone know the approx cost of a replacement from Skoda? I don't know any part numbers.

I need some new brake pads, possibly some new rear discs and tyres soon as well. Might be due to the cost I will go to a firm like National or ATS and try to negociate a discount.