Hi dori. I think.300 is a little steep.as he mite only be a day if that..
The materials aren't that expensive.either.
How about asking him to break down the quotation.with his labour cost. And how long the job will take.
Also.may be a good idea.to ask what materials he needs.and trying a little shop around.you may find youl save a little bit of money. .
As Joe stated that's prob about the rate.
Like he also said though you may also need a earth bonding upgrade. Check with your installer about this and also he will need to give you an electrical installation certificate for this work and also notify local council under apart P
I would say thats about right, some people would charge a bit more others a little bit less, it can also depend on how involved, the job is, for example you may need to extend wires to reach the new positions within the fuse board, or the installer may need to rectify faults found wilst testing, or need to upgrade the bonding, some people will include this in the price, others would say it £300, then once there doing the job alert you to the fact "it must be done in order to certificate," then charge more................For fuse board up grades, its probably best to get someone to look at the installation first, so there arnt any hidden charges..............Hope that helps