It is expensive due to the flex. I would recommend aganst buying a used one.
If it has any age to it I would suspect its life is compromised. The tube is under severe duty, going through a heating cycle every time the engine starts, seeing various and ever changing temperatures while driving.
Yours sounds like it eroded and created a hole. Holes can be welded. I am surprised it did not fail around the flare, which usually stays clamped in place while the tube separates from it.
If you intend to keep the coach spring for a new one. Or patch the old one as long and often as you can.