these people make good arguments for building your own, but remember buying one normally comes w/ a warranty and pre-assembled. your time is valuable so don't forget to add that into your decision making process

You should also mention that a warranty comes with loose parts as well.  And without any additional cost to get the 3 year warranty almost all manufacturs offer on their electronics.

Honestly, I can build a computer from scratch as long as I have all the parts in less than 30 minutes. Depending on how I configure the HD's I can even install the OS in that time. That's not alot of time when it comes down to it, especially with the savings you can get.

I've built probably 140 computers in the past 5 years, selling them to friends of mine (And friends of theirs via word of mouth) who want a killer gaming machine, but don't want to spend $3k to Dell or whoever for a top of the line machine and don't care to put one together. I don't charge them double like the big manufacturers do. I just added about $200 total to the cost it was for me to build it and get the parts so it was somewhat worth my time. Every single time it still beat comparable manufacturers machines at a significant savings.

Not to mention the 70 HTPC's that I have built as well.

Honestly, it's less expensive and you get higher quality parts in your machine buy building it yourself.

Dell and the big companies will save even more money not just from buying parts in bulk, but also by using a crappy video card, a poor quality motherboard, cheap Powersupply's, etc. Things that will affect your computer quite a bit. Keep in mind, they are saving themselves money, not you.

I know that building a computer yourself is intimidating, but trust me, it is absolutely worth it.

The first time I built a computer it took me hours upon hours to do, but with my 4th computer it only took me 30 minutes to put together. It may be a total hassle to work out some of the kinks, but you'll be better off in the end.