IMO you charge what you need to for your involvement and be honest in your report.
If I was evaluating a system with aluminum wiring I'd report on the need for a level of maintenance that is unrealistic to expect from a typical homeowner. I'd also report the dangers of non-professional repairs to the system, or replacement with wrong devices or connectors.
Then I'd recommend a complete rewire with copper wire.
From my point of view, that's an honest report on aluminum wiring. Too bad if the customer or insurance company doesn't like the report.
Dave
PS...and if the aluminum is to remain, I'd strongly recommend an interwired 120-volt with battery backup smoke alarm system to every sleeping area and every floor (with copper wiring).
