Building your own computer is pure hell. Only worth it if your a glutton for punishment and just have a ton of time on your hands.
After your build it decides to randomly reboot, what do you do? which component is it? Could be Power supply, motherboard, CPU, Ram or Video card. Do you return all of them? Hopefully you purchased everything from the same place.
I gave up trying to build my own after two machines i built had issues and it's just a nightmare of time to figure out whats going on and I just don't have that much time anymore. Don't get me started on the aftermarket cooling solutions. If you love a jet plane sitting next to you, by all means.
Do what I do, wait until Dell has a good sale (Nothing right now) Avoid the high margin upgrades. Order the extras yourself, ram and video card and you'll have a great solid top of the line machine at low cost.
I need to buy two new computers and i'm waiting for Dell to come out with a good deal. Right now they just want to sell laptops and netbooks.
I have built and repaired lots of machines, but I agree, it is not really economically the best use of your time.
These days computers are so cheap I just run out and get a new one anytime I get frustrated with the old one. Then I give the old ones away and claim that I dont no nothing about computers so dont ask me to repair it for them or anything else about it.
A few years ago I ran into problems with the computer I use for ripping for our imagesetter. I purchased a $350 e-machine, and discovered that it is far faster than the $5,000 computer that origionally came with the system. Now, the crappyiest computer you can get is 4 times as fast and has 4 times the memory and 4 times the harddrive of my emachine (which still works fine).
I used to be a big time computer geek, and I ran into everyone asking me to fix their computer (for free of course), so now I just tell everyone "I dont know nothing about computers."