You have two options these days when it comes to catalysts, you can go to a motor factor and get one which will be a pattern part and should cost around �70- �100. The other option is to go for a genuine Ford one which will be in the region of �250 or more! Then of course unless you do it yourself you will have to pay someone to fit it for you, I would replace the lambda probe as well as the old one will no doubt be seized in! Whatever you do though, don't go to Kwik Fit, because as well as treating you like a 5 year old they will charge an arm and a leg along with a few vital organs!!! I would query though why the cat should fail on such a relatively new car, cats should last 100,000 miles normally!