Reno is right on the button.
In commercial work, even really clever money saving tricks don't pan out: the GC WILL ( ABSOLUTELY ) spill those beans to his long-time buddy electrician.
( They always have such a buddy. )
Your finished work will be offered for inspection to your rivals. COUNT ON IT.
GCs would hate if it happened to them -- so they do it anyway.
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Which means that ANY production advantage HAS to be kept a secret -- meaning that it has to be something that can actually BE kept a secret.
Most of the time, such is simply not so.
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In commercial work the make or break is in the EXTRAS. GC's will try any number of ways to stiff you -- if the booboo is on them.
The Big Boys: Costco, Walmart, Safeway, Kroger, et. al. have absolute experts on their staffs. It's BRUTAL to get extras through their paper mill.
Leave that action to the guys with deep pockets. I've seen ##### wipe out at least two different seasoned contractors -- just in my neck of the woods.
( Never sign performance bonds with the Big Boys. It's suicide.)
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Since the buyers are few and the sellers / providers are many it's a MONOPSONY market. Google the term.
( One buyer & many sellers )
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You need to stop over building when ever possible.
You need to start customer charming when ever possible.
This pretty much means being his good-old-boy in manners and style.
It also means that you need an 'evil-bastard-in-the-office' who forces you to do mean things like get that EXTRA signed on the dotted line before you can proceed.
This is where many, many sole-proprietors miss the gambit: they have TOO MUCH AUTHORITY. Which means they don't have the authority to be OVERRULED by the 'bastard-in-the-office.' ( He's SO MEAN! )
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One example should suffice: I went shopping for a pick-up I already determined I wanted. Being a complete jerk, I brought along an abominable NO-MAN. EVERY time the salesman had me bobbing "yes" my No-Man was cold as ice. It seemed that there was ANOTHER identical pick-up at the other dealer that we'd 'promised' to look at before closing any deal.
This drove my purchase price down by $ 4,000 -- yeah, it took four hours.
Would you be willing to hustle for $ 1,000 per hour?
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I thought so.
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If a partnership -- the OTHER guy is ALWAYS the 'problem.'
If a sole-proprietorship -- dang, it's the OLD LADY. Yeah, she and my father-in-law have veto power if I take lousy deals....
If single/ divorced -- dang, it's my office secretary and bedroom squeeze/ fiance -- she'll cut me off if I tangle with her.
( Feel free to wear a fake marriage/ engagement ring. Get a used one from a pawnshop. )
[ If you're single, you'll be amazed at how many gals want to help you cheat on your 'marriage.' So it's a great ruse, generally. ]
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More generally, homeowners / general contractors are astonishingly clueless with regard to your skills. They've got their own worries.
Which means: win by being WORRY FREE -- and oh, so easy to deal with.
Cheers.