Inside trade tip. My BIL is a Sparkei by trade and I've helped him out on some jobs doing some labouring for him in exchange for work to my place.
He will pay $25 for a wall switch, then invoice you $50....
He will pay $15 dollars a metre for cabling, then charge you 40 a metre.....
Throw in labour at $145 an hour......
See where m going 😉
You can save bulk coin if you purchase your own gear, won't be trade rates, but it would be cheaper than what a Sparkie will charge you.