Well alot of that will depend on what they do afterwards. Ie do they spend time looking at what that is / could be, or do they just read off the faults.
£40 isnt far off what id say is reasonable, taking into account things like laptop and software like you say, £35!? so i guess with things like VAT also taken into account £40 isnt bad at all!?
Perhaps im guilty of camparing 'hassle' factor with other jobs done on cars..
But £65 at a dealer is steep and in many ways a dealer should be able to this cheap due to having the
resources, or even to provide a good service post sales.
Perhaps have the cost discounted against any repairs completed by said garage as a result or future service.