there should be a rule where if three gun docs with decent reps deem a gun to house a poltergeist, it should be destroyed or thrown into the oubliette for all to forget.
repairs, in my experience are only worth it if they are for complete newbs who forgot to switch a fuse or have some problem that hasnt been diagnosed and rediagnosed by a knowing user and never fixed.
with the undiagnosability of a problem, the price (assuming youre charging hourly or by lost brain cell count) VERY quickly skyrockets to the point of not being worth it anymore and generally speaking you only realize it's a bitch gun after several hours of mashing your face against it and who likes paying an hourly rate for a gun doc who couldnt fix their gun?
or lets say you bust your head on it for 4 hours and finally figure out that it's a small spring's fault. the spring costs 25c to replace and in their mind, the client feels that that should be the damage to their wallet and the payment for the labor is frustrating to have to dish out. but such is the curse of the gun smith.