On one side of the coin you have any moron, calling himself a repair man which can and does end in disastrous jobs which can be unsafe. This though has much lower pricing.
The flip side is, basically a protection racket where suppliers only sell to you if you have a 'loicense' and the hurdles required to become said VIP are so high, giving your body to a master tradesman to get a piece of paper over many years and be allowed to practice installing said systems results in a huge shortage of qualified people. Prices then skyrocket.
I wish I could live in a world somewhere in the middle, but as I've seen both ends of the spectrum, they both suck for different reasons.