If I were a busy sparky I would ignore lower value jobs where people supply their own product.
It reminds me of an insulation company I once tried to hire to insulate our garage, and they said they don't do that specific type of work anymore as government subsidies made other kinds of jobs more lucrative.
I was annoyed as I felt the government was pushing up prices for jobs like this. In the end, I couldn't find anyone local who would do it so I just did it myself.