I will put this under CPU as it is more of a question about the CPU:
My friend was looking at this for £445
Interface: Socket AM3+ FX 4170 4.2Ghz
Bus Speed: One 2200 MHz 16-bit Hyper Transport link
No. of Cores: 4
Core Name: Zambezi
Core Frequency: 4.20GHz
Clock Speed: 1333MHz
1tb SATA hard drive
AMD discrete graphics cards, ATI Radeon HD 7770
Interface CI Express 3.0
Memory Clock:4500MHz (Effective)
Stream Processing Units:640
Connectors: 1 x DVI-I , 1 x HDMI , 2 x Mini DisplayPort
Personally i believe an Intel i5 chip would be a lot better than this AMD chip.
1) Is it worth the money?
2) Intel or AMD processor?
I would not bother with any Bulldozer CPU. The Bulldozer is/was complete crap. It got beaten by pretty much every Intel CPU and couldn't even beat out the Phenom II it was suppose to replace. I would go with Intel for gaming since they are faster and more efficient than AMD's CPU's. If you really have to go with AMD though atleast go with the Piledriver.
Everything else is fine but I would get a better video card. The 7770 really is not that great of a video card for gaming. It is at best an entry level gaming card. I would at the very least go GTX 660 or Radeon 7850.