I have once bought a sword which has turned out to have hagire. It was beautiful, a sue-Soshu sword, I believe (or a Bungo takada, ha ha ha :-) ) The seller has offered full refund or a 50% price reduction. I went for the second option, and I have subsequently resold the sword clearly marked as one with hagire. I have thus managed to retrieve the purchasing price with no further hassle.
It was not a masterpiece, but a beautiful sword. I sometimes think that I should have kept it....
Pictures of the blade are attached. The hagire was hardly visible, it is very prominent, however, in the photographs....
Now, my problem is the following - many masterpieces have never been used in combat. It is possible that they would develop hagire if they were... We will never learn.