USAFRet :
1. Convince me. Why should I pay you $50 to build a PC?
2. "peoples exact budget" People do not know what they want. Or if they do, they'll just assemble themselves.
3. Warranty. What happens when something breaks? Can I call you at 2AM?
What do you personally bring to the table for this $50 construction fee?
I am NOT trying to rain on your parade. But just a few things you have to think about.
I'm asking people to pay me $50 to build a PC for the reason I mentioned earlier, I can build computers that perform much better than ones from Best Buy (I use that as an example because that is the only place to buy a computer in person where I live) at the same price. This also means you can get a PC that performs the same as a Best Buy one for less.
If someone has a budget to spend on a PC, I can get them the best performance for that amount, or if they don't I could find out what they are using it for and put a build together to match. For example, let's say someone is just doing some basic multitasking work and they just need something that performs well and they'd be willing to spend $600. This prebuilt shows up on the front page of Best Buy when you go to the desktop section.
Lenovo PC
So they think, "well it says i5, 1 TB, and GT 730, sounds like it must be pretty good." It isn't necessarily a bad PC, but it is overpriced (it's hard to imagine that they charged $650 for it at one point). I just spent a bit of time putting this together to show what I would put together for that price.
PCPartPicker Build
I would round that off to $610 for a profit of about $45. This one is far superior in my opinion and it costs much less (only $10 more including labor).
If something breaks, I'd be willing to handle the RMA if applicable, and if it is not covered, I would charge $10 to replace it plus the part cost. I wouldn't pick up the phone at 2 AM, but I would be happy to help the customer get their computer up and running as fast as possible. If it is a problem that requires someone beyond my skill level to fix, I's refer them to a computer repair specialist.
Later, if the customer wanted to upgrade, they could either buy the part and I would install it and charge accordingly, or they could give me the old part and I could give them credit for a new one.