I understand that this is a few weeks old however.
Would be interesting to know the age of this installation and a photograph of the DBs as it looks like an older installation with multiple radials. Very difficult to comment without a reasonable amount of detail.
Problem is that the customer is looking for support for their surprise in the final cost, possibly to support a complaint.
It may well be that the installation is old and rambling, and that the sparky done a good job and should have charged more.
That's why it is worth asking how many DBs, fuses, breakers they have prior to quoting. I understand that everyone may not be able to answer this so a quick visit may be required.
When replying to members of public with these sort of questions I think that some caution should be exercised in the replies as it could potentially damage the electricians reputation.
No dig intended to anyone who posted a reply, just my thoughts.