Guess I'll add my two cents. Built my PC about two years ago and still a great machine - still runs all the new games and runs fast. Building your own PC definitely has its ups and downs. Buying a pre-made machine is cheaper in most cases now a days...simply for the fact that they are mass produced by large corporations and they can lower the retail and still make the same amount of money. But building allows for much better customization; most of the machines are made for word processing, internet, and pictures because this is what most user use their computer for. Personally, I made a machine because I have lots of video and play games - I needed a better video card and more hard drive space. There is no mass produced machine that is like my machine. If you only use a computer for word processing, internet, and pictures, I would personally recommend purchasing a pre-made machine because you wont have to build it and it comes with a warranty. When I buy "backup" machines (anything but my primary), I buy from companies for this reason. My machine, at the time it was built, was essentially the worst of the best (if that makes any sense at all). It wasnt the bleeding edge but it was the lower end of cutting edge. And, in the end, my machine cost around 2,200 (not including monitor). The good things about building your own PC include customization, price in some instances, being able to install a good mobo and power supply (lot of corp. skimp on this), fun (for some), etc. But it can also be aggravating. If a product is shipped and doesnt work, you have to ship it back and wait for it to get back to build your computer (this is also true of products you may break while installation or compatibility issues you didn't know about). Price, for typical machines, also increases when you build your own machine.
In the end, the important questions to ask yourself are...do I need a custom machine for what I use a computer for? Do I know how to put it together, can I look up a tutorial, or do I have someone who can help me put it together? If you need a custom machine, you know what you need. If you want to build because you want a beast or a price break...usually better to buy from a company. If you want to build, and can build, because you need/want a custom machine...definitely build. Cost about 1500-3000 for a good machine (just the tower). Any more specific questions...please feel free to ask. Just figured I would just add a quick blurb with my opinion. Cheers.
"I wonder if I've been changed in the night? Let me think. Was I the same when I got up this morning? I almost think I can remember feeling a little different. But if I'm not the same, the next question is 'Who in the world am I?'"
"Vi Veri Veniversum Vivus Vici..."
"Not much really" - Sidis