Front flexi has a blow in it and needs replacing?

I've just bought a car off autotrader and in the last service report in January it says the front flexi has a blow in it and needs replacing. You can hear it makes a throaty noise and the owner did mention it up front.

I've just called a garage and he said he has to change the catalytic converter at the same time and quoted £280 inclusive of labour. My question is does he need to change e catalytic converter at the same time and also if yes is this a fair quote?

It's a 2007 VW Golf 1.6 S FSI.

Many thanks for your advice.

Nick