I just repaired mine yesterday, I cut the pipe about 50mm from the flange, sleeved the pipe & welded a new flang on the end, was pretty tricky getting the alignment set & holding it in place whilst removing it from the car to weld,
If your going to take it to a garage to just get the hole welded it will probably cost you say £20-£30, but if you want someone to mess about replacing the flange & sleeving the pipe like I have done you could be half way to getting a new exhaust.