One of you mentioned £300 + . There's no way I'm paying anyone that much. If necessary, they can fit the main supply cables then go. I'll fit the house circuits back in myself.
I suggest you try to catch up with reality.
Replacing a consumer is not like putting up a shelf. It takes a great understanding and knowledge which takes years of training to be carried out safely and correctly.
I install domestic fuseboards for around £200 plus the cost of materials, and I think I'm very cheap some days.
What you have said is insulting