First off, I apologise for kinda doing the complete opposite of what you asked by making the build MORE expensive rather than less. I'd still say it's good value though honestly.

Your build is fine from a price/performance view and there is nothing specifically wrong with it but an R7 370 is better than the 750 TI so for comparatively a little bit more you get a good amount of extra performance, and the 370 is crossfire capable if you ever wanted to do that, but remember it is always better to buy a stronger single gpu rather than 2 weaker gpus. Crossfire is good if you happen to come across a second hand card on eBay or something that you feel like picking up for £50 or something.

The i3-4160 is good, very small difference between that and the i3-4370 which is the most expensive Haswell i3. I would recommend getting an i5-4460 though if you are thinking about games that would struggle with the Pentium G3258 because 4 real cores will always beat 2 HT cores. In fact, I'd go as far as to say if you're playing multithreaded games then you could buy the 4460 and then use the iGPU on that for a month and not play any graphically intense games then get a 370 a little after Christmas, I don't know how old you are so I don't know if you have a job or what.

As for the motherboard, the one you chose is good and if you want to go for that one then do, there's no particular advantage that the one I chose has over the Gigabyte board. I only chose this one because I have the Z97 variant of it so I know it is a solid board. Also, just look at those orange heat spreaders on the Gigabyte board, not quite to my taste.

Xigmatek make good products, I have a Xigmatek case myself (Not the one you chose though) and it is great, it has plenty of room and many unexpected features.
The case you chose however.... not quite as premium and I think you would end up having to get a new case within a few months, there's a difference between value and cheap. The Recon case is just cheap.

Kept the PSU because it's decent and again, is the same as what I use so I know it works. Since you won't be overclocking your CPU you don't need a super stable power supply, and even if you got an unlocked CPU you can still overclock using this PSU anyway because it is quality. (Able to get a 3.2GHZ Pentium to 4.8GHZ without any issues)

Like Noxie said, an SSD will really speed up performance in desktop applications but there is no reason to store games on it because the amount of money it takes to buy an SSD with enough room to store all your games is not worth it. Not to mention there is no frame rate gain by installing games on a faster storage device, the only gain will be slightly shorter loading times which is good for single player games but awful for multiplayer games when you'll be playing against people on HDDs anyway and will have to wait.

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-4160 3.6GHz Dual-Core Processor (£89.99 @ Ebuyer)
Motherboard: MSI H97 PC MATE ATX LGA1150 Motherboard (£65.81 @ Amazon UK)
Memory: Kingston HyperX Fury Black 8GB (1 x 8GB) DDR3-1600 Memory (£31.08 @ Amazon UK)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive (£34.45 @ Amazon UK)
Video Card: MSI Radeon R7 370 2GB Video Card (£111.17 @ More Computers)
Case: Corsair 200R ATX Mid Tower Case (£49.98 @ Aria PC)
Power Supply: EVGA 500W 80+ Certified ATX Power Supply (£29.99 @ Aria PC)
Operating System: Microsoft Windows 10 Home OEM (64-bit)
Total: £412.47
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-12-06 16:36 GMT+0000

Like I said at the beginning, there is nothing specifically wrong with your build and it will perform well, better than a Pentium in games that can use the extra threads but worse than an overclocked Pentium in games that can't. 3.6GHZ cores will never beat 4.5GHZ cores in games that are single threaded, or barely benefit from more than a single thread.

Thanks, I think I do have a spare SSD from my previous pc lying around - Ill be sure to add that in.

Also 53MP3RF1 I am aware of the cost, thats why I want to keep the cost down to lower.

Looks great! If think you can extend your budget by a bit, I would recommend getting an SSD as well - 256 GB should do just fine. You can store games & the OS on it, and expect a faster performance as well as a quick bootup.

This will be a great build for what you're needing it to do. I assume you're going to play games, and the R7 360 is only slightly less powerful than the 750 Ti you had previously - plus, it has full support for DirectX 12. I also put in an FX-6300, which although it is an aging card, it will outperform any i3 (not to mention, the Haswell sockets are outdated as well, because Intel's releasing Skylake processors now - not to say they aren't still viable, but they are in the same boat as AMD's current processors). I changed the RAM out for some slightly slower RAM, but your processor wouldn't have been able to take advantage of the higher frequency in the first place, and CAS latency is more of a bragging thing than an actual performance metric (it's a difference of nanoseconds in RAM responsiveness). I also changed out the case for a different one, which should serve your needs well. It has an included 120mm fan at the rear, and I also included a 120mm fan at the front.

I wouldn't overclock this computer, simply because you're running an OKAY power supply, but not a great one - plus, you'll have only the stock cooler on the CPU.

Also, you realize that Windows has no price on the PCPP website, right? It would be somewhere in the neighborhood of £70-£90 to buy a copy of Windows from retail.