I jumped in with both feet full time two years ago. I wish I could say I make money. I lost more than made doing this last year. As mentioned above, getting clients is somewhat difficult. More so in my case as I have developed a very bad case of impaitience for idiots - hence the name Byte M.E. Computers.
I started by aiming at the home market. I think if done properly there is considerable money to be made. That's if you advertise and get some good customers to pass the word along. But the only money your gonna make there is from doing upgrades with an occasional format here and there. That's because they already own computers and don't call unless something isn't working.
As for new builds consider how you advertise and the price. When I first started I thought I could compete. I can't and don't try. You yourself are not going to be able to buy the parts, software, pay the shipping, put it all together, install the o/s, tweak everything and then sell it for $699 monitor included. Dell, HP / Compaq, and Gateway can do this. If you were able to buy all of the parts and o/s for say $700 and you sold it for $800 - that's $100 profit. Now think of all of the time you spent on the net looking for the best deals, the build time, the troubleshooting time (if any), the time to deliver and setup (I include this as a selling point) - that hundred bucks doesn't seem very good.
Another point to make is not to use cheap parts. You have to stand behind a warranty. Cheap drives
will fail and although you can RMA it within a year, your labor is free and you'll more than likely have a mad customer. Same goes with any hardware. Word of mouth goes both ways. I am amazed at how some of the computers are built / configured by local shops that wind up coming my way. In thier quest to save time and money the lost a customer and I gained one

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As for charges. I don't think you want to do it the way I have been. I never set a rate table up and basically charge by the job. That can lead you right into the poor house with me

. I made the mistake in being overzealous. I never charged for a house visit (that's all I do). That said, there isn't any customer within 20-30 minutes from where I am. That's an hours time / gas and over a mountain in any direction I have to go (sucks in the winter).
And this is what most of the calls are like: A guy called last week and wanted my advice on why the burner he tried to install in his girlfriends computer (Packard Bell 133) wasn't working (grinding my teeth right off). After about 20 minutes of him picking my brains (for free), I told him that I would have to come see what he had done (about a 35 minute drive one way). He asked how much and I said I charge $40 to install a drive. I pulled that number off the top of my head - it was 8:30pm on a Sunday when he called. I should've charged more 'cuz he got 20 minutes of my time for free already. I said I'd be there in the morning. He wasn't able to pay until Friday so I told him to call me back then. He did and I drove through a white out to work in the most filty enviroment I have ever been in. It took 2 hours to get the computer to boot because he "was doing something in the registry" which wiped it out. I think I spent the $40 in cleaning my clothes and myself. Tomorrow I have to go see another guy who wants a new computer for $400. That dog ain't gonna hunt.
Wizz, I too wish I could do just custom builds. But in my area, there aren't enough experienced users to aim for. People just don't want to shell out $1500 for a rip roaring box but will shell out $1300 before rebates at Staples for a cr@p Compaq. I can't figure it out

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I know that really didn't answer all of the questions exactly - just sharing a view from the side that's here and struggling to make it in a world full of cheap, moronic people (present company not included

)

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BTW, buy lots of Ramen

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Mike