build vs prebuilt

[jd10013]

been thinking about upgrading my current PC, so been looking around seeing whats out there. I thought this time I would build. in the past, I've always just bought prebuilt, done an upgrade or two after a few years, then replaced. but everyone always says how much you can save building yourself. anyways, I was poking around on dells website, and saw that they have a new computer available, and XPS 8900. one of the configurations comes with an i7 6700 4.0 ghz, 8 GB ram, 1 TB HDD, and typical mouse, keyboard, dvd writer yada, yada yada. but what caught my eye was they're selling it for $949, with an instant $100 off, plus a coupon through the 22nd for 10% off ($85) for a total of $764.99. seems pretty cheap for a 6700. Newegg prices them at about $370. and with nearly $400 going to the processor, I don't see how I could do a build under $764 without downgrading the processor. especially considering having always bought prebuilt, I'd have to fork out another $99 for a copy of windows. am I missing something here?

edit: I know it would come with a crap GPU, but I have a R7 370 on the way.

 

[Shlouski]

http://www.ebay.com/itm/CORSAIR-CX-...879288?hash=item43d20d0c38:g:yMMAAMXQE9hSA~-k

Corsair 600w - 65 dollars

http://www.ebay.com/itm/New-1TB-100...246198?hash=item1c2f92fbf6:g:x~oAAMXQUY1RAfXV

1TB HDD - 36 dollars

http://www.ebay.com/itm/ZALMAN-Z5-B...866770?hash=item43d20cdb52:g:l9wAAOxyItlSNK8t

Zalman case - 30 dollars

http://www.ebay.com/itm/Intel-Core-...591787?hash=item46419e1cab:g:LWoAAOSwWnFWBXIs

Intel i7 6700k - 370 dollars

http://www.ebay.com/itm/Gigabyte-GA...296117?hash=item35f090ebf5:g:a7kAAOSwhAZWBe~k

Z170 Motherboard - 100 dollars

http://www.ebay.com/itm/16gb-Corsai...019504?hash=item2a5a531030:g:nSQAAOSwI-BWIASz

16Gb DDR4 - 100 dollars

About 700 dollars without OS

I'm not saying buy these exact parts, its just example of the route you could take if you planned to build your own system. This is only using ebay, being from the uk I don't know the best sites to shop from in the US, but I'm guessing if you shopped around a bit more on other sites you could probably save a little more on the same or equivalent parts.

Edit: If you install a new GPU you might also need to upgrade the PSU in the XPS depending on what it comes with, normally they use the minimum they need to do the job.

Just found that its a 460 watt PSU, AMD recommends a minimum of a 500w psu for the R7 370.