Exhaust problems

Okay, so my clio is 4 years old with 70k, ive already had a milltek exhaust but sold it.

The secondary CAT is now starting to develop an annoying rattle and needs replacing, firstly does anyone know how much a standard full system with CAT would be...

...secondly has anyone removed the secondary CAT and got through the MOT with a full milltek or k-tec system on??
 
Not a great deal of help but I defo saw on eBay not too long ago a full 197 system for like £100 I think.
 
Yeh, they are second hand and dont want to buy one for £100 and it go again. Plus you have to drop the rear beam out to fit the single piece unless i cut it and reweld it