A Question For The Steem Community: How Much to Charge for a Custom PC Build

Hello Everyone,

A bit of backstory, I was approached by a coworker and asked to build them a PC for their home. It is not unusual for people at work to ask me about what tech to buy or have me pick out or find a good deal on a computer, but I have not been asked to build anything until now. I had initially offered to just build it and bring it in free of charge, however, the person who asked me to do this insisted on paying me. So far my research has only uncovered suggestions on hourly rates but this seemed unreasonable to me because things like installing the OS and drivers would artificially inflate the price, and charging any reasonable sum might push the cost into territory where just buying an off the shelf model would be more economical. I am leaning towards 50$ because that will cover the gas to go install it and still leave me with a bit left over while not being too ridiculous (for reference this person's initial offer was 500$ on top of the cost of parts). The build will be a relatively powerful machine with a lot of HDD space for photo editing and general home usage.

My question to you all then is, was my number reasonable and if not what would you do in my position?

Thank you all for your advice.