Any recommendations for the cheapest place to get the back box on a 2000 Vectra Diesel replaced?

Big rust hole on the current back box with the MOT due.

Buy one from lvw cleverland street, and fit it yourself, very easy to fit, and you will save quite a bit of money

Thanks for the advice, although the phrase "very easy to fit" probably doesn't take into account my total ineptitude doing anything practical.

The hard part is getting the old one off without damaging the middle box tailpipe.

I supposed it was inevitable but I managed to damage the tailpipe thingy. Now to find a exhaust welder :-(