There is no Guitar Builder's Union as far as I know, and probably as wide of variability in pay scale as the Mississippi. Guitar builders mostly get paid for their reputation and their completed product. There is no hourly scale to apply to building a guitar, as far as I can see. You get to charge as much as the market will pay for your complete guitar, which will likely range from $200 to $25,000 depending on your skill and reputation.
Now, the professional techs in my neck of the woods charge about $120 for a complete setup. What's that, maybe 1-2 hours, so maybe gross anywhere from $60 to $120 an hour. But I'll guarantee you, if they started building complete guitars by hand, they would not get anywhere near that wage.
I really wouldn't try to apply a "wage" model to pricing guitar builds. It's a totally different beast.