I am a commercial electrician, as such I tried to wire my mothers wet room, following all the rules as social services involved, in Wales so can't use another electrician to sign off work, only the LABC route is open to me.
The LABC however can delegate the work of inspecting to an electrical firm, and you the owner have to pay for that inspection on top of the LABC fee which in Wales is £100 plus vat for first £2000 worth of work. So minimum cost to do notifiable work is around £200.
If you look at new English landlord laws and the EICR you will see a huge difference in the standards expected by different electricians doing the inspection, and the rules and laws are not all electrical. HSE, and building regulations stipulate distance from corners, socket heights, and many other requirements, and some are to be frank daft.
So if some thing needs to be viewed then max and min height, but if it needs manual operation also max and min height, so the height of a thermostat is fixed at 1400 mm, but you can still mount it on the end of a radiator, which is clearly too low for regulations, one hopes common sense will prevail, and I am sure with the radiator TRV head it would, but your at the whim of the inspector, it is not so much right and wrong, but 50 shades of grey, and it is likely you will need to redo some items.
It is not the redoing which is a problem, it is the charge for another inspection after the changes, and the time it takes, each time you do something the LABC has 14 days to inspect, unlikely to take 14 days, but it means multiple breaks in the rewire waiting for permission to continue, and you need permission to turn on power, which is a big problem if also living in the house.
As I say your at the whim of the inspector, he may permit you to power up before inspection, but in real terms it can cost more to DIY a rewire than to use a scheme member to do it.
So when it came to do a full re-wire of mothers house, I used a scheme member firm, OK there was a time constraint. It was costing £650 per week to have mother in a care home while house was rewired, so speed was important. I had a basic re-wire, all sockets to be on a ring final, so I could add spurs latter, and the kitchen and wet room had already been rewired, so seem to remember around £3000 of which at least £1000 is materials, so labour £2000 and there were between two and six men on the job and was completed within a week.
Had I done it, looking at more like six weeks, hard to pull cables on your own.
So have not talked about training, as I already had the qualifications, it is the getting of each section signed off by LABC. To become a scheme member you need to do a couple of rewires and have them inspected, so for one house, that's a non starter. It is not a case of do the course take an exam and start rewiring as a scheme member.
If the rewire is part of a larger project then using the LABC may be an option, but in the main it's a non starter.