You answered a question I have not asked yet.

I asked
"If a collector has drilled high end chips repaired to make them substantially more valuable, do you think he should deny those chips were repaired?"

I will rephrase it:
If a collector has had chips repaired, do you think he should deny it if asked?
(nothing to do with offering to potential buyers)

I realise my definition of 'repair' or 'altered' may not concur with yours. In the question above, I was referring more specifically to things such as invisibly filled drill holes.