Any reasons for the G258 if you don't plan to overclock? I would look into the Athlon X4 860K if I were you (it has 4 cores vs. the G258's 2 cores and is clocked faster at 3.7 GHz). Here's a build with the X4 860k that is within your friend's budget. The case I picked out is a CM N200 that is marginally more expensive than the Core 1000 but offers some room for cable management.
PCPartPicker part list / Price breakdown by merchant
| Type | Item | Price |
|---|---|---|
| CPU | AMD Athlon X4 860K 3.7GHz Quad-Core Processor | £53.83 @ Scan.co.uk |
| Motherboard | MSI A88XM-E35 Micro ATX FM2+ Motherboard | £37.87 @ Amazon UK |
| Memory | Crucial Ballistix Sport 4GB (1 x 4GB) DDR3-1600 Memory | £30.96 @ Amazon UK |
| Storage | Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive | £35.94 @ Aria PC |
| Video Card | Gigabyte Radeon R9 280 3GB WINDFORCE Video Card | £144.99 @ Ebuyer |
| Case | Cooler Master N200 MicroATX Mid Tower Case | £29.04 @ Scan.co.uk |
| Power Supply | Corsair CX 500W 80+ Bronze Certified Semi-Modular ATX Power Supply | £44.99 @ Scan.co.uk |
| Wireless Network Adapter | Asus PCE-N15 802.11b/g/n PCI-Express x1 Wi-Fi Adapter | £15.58 @ Scan.co.uk |
| Total | ||
| Prices include shipping, taxes, and discounts when available | £393.20 | |
| Generated by PCPartPicker 2014-12-28 13:58 GMT+0000 |