I this a Beast of a Machine?

Solution
PCPartPicker part list / Price breakdown by merchant

CPU: AMD FX-6300 3.5GHz 6-Core Processor (£79.19 @ Aria PC)
Motherboard: Gigabyte GA-78LMT-USB3 Micro ATX AM3+ Motherboard (£39.59 @ Aria PC)
Memory: Kingston Fury Red Series 16GB (2 x 8GB) DDR3-1600 Memory (£74.31 @ Amazon UK)
Storage: Kingston SSDNow V300 Series 120GB 2.5" Solid State Drive (£40.63 @ CCL Computers)
Video Card: Gigabyte GeForce GTX 960 2GB Video Card (£148.00 @ Aria PC)
Optical Drive: Lite-On iHAS124-14 DVD/CD Writer (£9.96 @ Aria PC)
Other: AeroCool Cyclops Red/Black (£35.49)
Other: Aerocool Templarius Imperator 850W 80+ (£81.58)...
I'd say it's not worth it, an FX 6300 with a GTX 960 is a good combo, but you're paying a bit of a premium for 16gb of RAM that you most likely won't even need, the PSU is absolute junk, you need to get your own OS and only 120gb of storage?
 
PCPartPicker part list / Price breakdown by merchant

CPU: AMD FX-6300 3.5GHz 6-Core Processor (£79.19 @ Aria PC)
Motherboard: Gigabyte GA-78LMT-USB3 Micro ATX AM3+ Motherboard (£39.59 @ Aria PC)
Memory: Kingston Fury Red Series 16GB (2 x 8GB) DDR3-1600 Memory (£74.31 @ Amazon UK)
Storage: Kingston SSDNow V300 Series 120GB 2.5" Solid State Drive (£40.63 @ CCL Computers)
Video Card: Gigabyte GeForce GTX 960 2GB Video Card (£148.00 @ Aria PC)
Optical Drive: Lite-On iHAS124-14 DVD/CD Writer (£9.96 @ Aria PC)
Other: AeroCool Cyclops Red/Black (£35.49)
Other: Aerocool Templarius Imperator 850W 80+ (£81.58)
Total: £508.75
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-06-21 13:15 BST+0100

I wouldn't consider £33 a "massive" discount and there's no OS included.

-Wolf sends
 
Solution
This has a better CPU, PSU, and HDD for £25 more. Arguable the GPU can be better.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i5-4460 3.2GHz Quad-Core Processor (£141.26 @ CCL Computers)
Motherboard: MSI H97 PC MATE ATX LGA1150 Motherboard (£61.16 @ Scan.co.uk)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory (£39.99 @ Dabs)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive (£37.44 @ Aria PC)
Video Card: XFX Radeon R9 280 3GB Double Dissipation Video Card (£149.98 @ CCL Computers)
Case: Corsair SPEC-01 RED ATX Mid Tower Case (£41.94 @ Aria PC)
Power Supply: EVGA 500W 80+ Certified ATX Power Supply (£33.78 @ Aria PC)
Total: £505.55
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-06-21 13:24 BST+0100
 


You missed my point. They're offering that system for £475.99 and claiming a £328.43 (40%) discount. They're saying the total cost of the build before discount is £804.42

If you'll look at the build I provided, it's the exact same specifications (identical parts when possible) and the cost was only £508.57

They say you're getting a £328.43 discount. What I've shown you is that it's only about £33.

-Wolf sends