I charge people $150.00 USD to build them a computer, install OS, drivers and other software that comes with parts. IF they want me to transfer DATA from old PC or install other appz or set it up in their home, i charge $200.00 USD.
It's roughly 4 hours worth of work total. 4/150=$37.50 per hour.
I just finished 1 PC for a client and they spent 1,300.00 on parts and S&H. 150.00 labor. total of 1450.00
They were going to buy one from "DELL" and it was 2,100.00. I yelled at them, brought them to newegg.com filled up a shopping cart with much better parts, same specs, told them my labor charge and they payed me $150.00 labor on the spot.
Word of mouth gets me a new client almost every other week.