Budget NAS Build

[BluPaperclip]

Copied from my PCPP thread, sry

I'm looking at building a NAS around black friday for storing all my stuff on. This includes some semi-important projects, so you can see why I want to move away from my 3 year old Seagate drive.

Budget: As cheap as possible really. Preferably under £400, but I'm willing to go over a bit.
Location: England
Use (Gaming, Rendering, etc): NAS
Peripherals required (monitor, keyboard/mouse, etc): I have some junk ones, so no
Operating System required: FreeNAS will be used.

Also, can someone tell me if getting ECC RAM is worth it at this price point. I know it's recommended, but how often does normal RAM fail?

Non ECC:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Pentium G3258 3.2GHz Dual-Core Processor  (£63.90 @ Eclipse Computers) 
Motherboard: MSI H97 PC MATE ATX LGA1150 Motherboard  (£71.99 @ Ebuyer) 
Memory: Corsair Vengeance Pro 8GB (2 x 4GB) DDR3-1600 Memory  (£39.95 @ Amazon UK) 
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive  (£44.13 @ Amazon UK) 
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive  (£44.13 @ Amazon UK) 
Case: Cooler Master N300 ATX Mid Tower Case  (£49.99 @ Amazon UK) 
Power Supply: Corsair CXM 450W 80+ Bronze Certified Semi-Modular ATX Power Supply  (£49.99 @ Novatech) 
Other: Boot Flash Drive (16GB) (£6.18)
Total: £370.26
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-11-13 10:21 GMT+0000

 

ECC:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Pentium G4400 3.3GHz Dual-Core Processor  (£52.15 @ BT Shop) 
Motherboard: Gigabyte GA-X150-PLUS WS ATX LGA1151 Motherboard  (£93.04 @ Novatech) 
Memory: Kingston ValueRAM 8GB (1 x 8GB) DDR4-2133 Memory  (£46.23 @ Amazon UK) 
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive  (£44.13 @ Amazon UK) 
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive  (£44.13 @ Amazon UK) 
Case: Cooler Master N300 ATX Mid Tower Case  (£49.99 @ Amazon UK) 
Power Supply: Corsair CXM 450W 80+ Bronze Certified Semi-Modular ATX Power Supply  (£49.99 @ Novatech) 
Total: £379.66
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-11-13 10:20 GMT+0000

 

And obviously, I will look at the best details on black friday. Also, I may consider getting 2TB drives instead (seagate or if the sales are really good, WD Red)