A point from the other side:
When, as an ordinary householder, you ask for quotes, it's very hard to sort out the wheat from the chaff. It's a few years back now but I remember when I had my house rewired. I got three quotes - one guy arrived in a smart new van; insisted on putting covers on his shoes while he had a look and subsequently quoted what I thought was a silly price. (I assumed that he had decided that he didn't want the job).
Number two, I don't remember much, but he was in the house for barely five minutes and his quote was the lowest of the three.
The guy who got the job was a one-man-band and it took him a lot longer than he had thought - I suspect that there was not a lot of profit left at the end, but he did a good job (I think) and I got a certificate to prove it.
It's possible that the first guy would have been a lot faster, or the second one may well have just counted sockets @ ÂŁ30 each and added 50% - then gone on to do a decent job and saved me some money.
My point is that when someone says they are a qualified electrician and offers to do the job, all we can go by is a gut feeling about them and the price. If number two had turned up in smart overalls with a logo on the pocket, and spent an hour taking notes with a stubby pencil, he would probably have got the job.