Hook everything up yourself that you can handle and pay a "guy" to come do the brazing and charging lines......or anything else you can't or don't want to do.......don't just assume because some guy is licensed that he know his butt from a hole in the ground.....go off of referrals. There are a lot of incompetent contractors out there...
The other day my guys and I watched an electrician fumble around trying to drill conduit through concrete for 4 hours using a normal wood bit instead of a concrete bit....I told the owner to not bill me for those wasted hours due to incompetence...and that I never wanted to see that guys face again on any of my jobs.....
That's part of the reason i feel that these jobs get too expensive..... You need to know this stuff so you know when a contractor is incompetent or screwing you. Most people would never questions a guy trying to drill through 8 inches of concrete with a normal drill and bit....and when it takes hours for someone to come along and correct him, guess who gets to pay $100 plus per hour for all that wasted time???? I assure you its not the electrician.......He will probably just tell you that there were some unforeseen problems that popped up and they need more money to finish.........ha ha..
Uneducated homeowners get taken advantage off all the time and don't even have a clue........They just know its going to be very expensive but question very little.
I get furnaces installed by a professional that took me years to find. A 90% 80k btu furnace I just had replaced because of a cracked heat exchanger cost me $1840 total and I know my guy is making good money......he's just not greedy.
I know this business from top to bottom and I still don't know why, (actually I do)...I HAVE to hire an overpriced "pro" just because an government inspector tells me too......If I pull the required permits myself AND my work passes all inspections......someone other than a lobbyist please explain to me why I'm required to hire someone to do something that I can do myself.....