just a quick example of a DIY list of components
AMD FX-4100  cpu  build   ( FX-4100 newegg combo # 765930 )
-AMD FX-4100 Zambezi 3.6GHz (3.8GHz Turbo) Socket AM3+ 95W Quad-Core Desktop Processor FD4100WMGUSBX  
-GIGABYTE GA-880GM-USB3 AM3+ AMD 880G USB 3.0 HDMI Micro ATX AMD Motherboard  
-G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-4GBRL  
-Rosewill R218-P-BK Black SECC Steel ATX Mid Tower Computer Case  
-COOLER MASTER eXtreme Power Plus RS500-PCARD3-US 500W ATX12V v2.3 Power Supply  
-Seagate Barracuda ST31000524AS 1TB 7200 RPM SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive  
-LITE-ON DVD Burner - Bulk Black SATA Model iHAS124-04 - OEM  
-Linkworld Electronic LLC FAN-9 90mm Case Fan - OEM  
was: $486.92 
Discount: -$56.93 
Combo Price:$429.99 
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then add a Video Card:
-MSI R6770 Twin Frozr II/OC Radeon HD 6770 1GB 128-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card
 
Radeon HD 6770 1GB GDDR5 PCI Express 2.1 x16 Chipset Manufacturer: AMD
Core Clock: 875MHz
Stream Processors: 800 Stream Processing Units
Effective Memory Clock: 1200MHz(4.8Gbps) 
Model #: R6770 Twin Frozr II/ 
Item #: N82E16814127590 
Return Policy: VGA Standard Return Policy 
Now: $139.99     ($119.99 with Rebate) 
$7.56 Shipping 
 
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Total = $569.98  +  Shipping & Taxes if taxes apply  ( Even costs Less after the rebates )
compared to the cyberpower prebuilt PC this example combo deal has Better/Faster System Ram, USB 3.0,  SATA III 6.0 GB/s ports & 1 TB SATA III 6.0 GB/s  Hard Drive, better Northbridge chipset
you can opt for a Rosewill media card reader 40 in 1  for just $7.99 more  free shipping
and you will need to purchase your Windows 7 Home/Professional/Ultimate  64 bit  SP1   OS ( oem dvd disc )   this will cost around 119  to 189 depending on the version you want, although you can get the upgrade win7 from microsoft store via student at a cutrate cheap price, if you have a student id or a family member does........ last check was around $30 or so......  I heard these worked just the same as a full price installation dvd of the retail version......  YMMV
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NOTE: ONLY FOR illustration / example purposes............ am not recommending buying this!
I would not purchase the  System Ram though, I would opt for Corsair Vengence  1600 MHz  8 GB ( 4GB DIMM x 2 ),  and I would search for an AMD AM3+ cpu socket Motherboard that had a 990 Northbridge chipset,  or at least 890 minimal
I only picked the Videocard to match the same model in the prebuilts, although the model I selected is far and beyond better than the prebuilt versions of the same VC, regarding the "msi twin frozr II model", I selected
Remember this is just a quick example of extremely better components  verses buying the above linked pre-built PCwith the FX-4100 cpu
hope this helps ( helps shed why I recommend you build your own or keep searching )
TC