£100+VAT (-VAT if you pay cash 
) all in, including removal and refitting, if you take the mid pipe in yourself, they'll do it for £60, bargain 
They had it done in less than one and a half hours, including welding a broken hanger up for me as well.
Very, very impressed with the speed and the cost. £60 to replace a flexi (including the flexi!) is a win/win.http://www.haywardandscott.com/