I dont know what it is, but I am always looking to upgrade my PC, If I bought sensible priced parts My PC would have cost around 40% less, bought PC in 2012 october. !the 10th to be precise

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coolermaster HAF x case £130.
Headset - £50,
Keyboard - £30
mouse - £60 Logitech G600
Boogie large mouose pad - £25
Motherbaord MSI Big Band z77 - £155
CPU - i5 3570k £170.
Zalman Aftermarket Cooler - £40.
GPU - MSI 7870 Hawk Edition £200
RAM - Kingston Ram Hyperx 8gb grey - £33 (Yes ram was SO CHEAP BACK THEN, I regret not getting 16gb, same RAM cost £60 now :O)
Sound Card - Asus DG and DGX sound card, £20 each, Bought the DG version wasent compatible with MB so I bought the PCI E version, I still have the DG unopened for some reason I decided to keep it.
SSD - Samsung 830 128GB - OS, OCZ agility 90GB - £60 (I think) - most played games
Now I have sold my GPU for £155 (not bad) and got the MSI GTX 670 power edition for £200, and it came with 2 games, splinter cell and batman arkham origins, so basically I got the GPU for free.
Got a 1TB blue WD drive for steam +windows backup. £50
Now I have another Mouse for FPS gaming, Logitech G500s - £60. My G600 still works but never hurts to have a backup mouse, or when a game has lots of keys I will use it.
Just recently I did a MASSIVE maintenance on my PC, re did the whole cable management, bought all the braided extension cables you can think off, cost me around £60.
Bought a 140mm and 200mm spectre fans for my HAF x, £20.
Some Cathode White LEDS £10.
A Crucial M500240gb SSD - £100 !!!!!!!! Was half price and couldent pass on a offer like that, so Will install BF3, BF4, Dead Space 3, BF 1942 all on that drive, and my most played Steam games, such as counter strike e.t.c.
Another SSD Crucial m500 120gb - £50! Another deal that I couldent pass up, THIS drive will replace my OCZ 90gb ssd, and will have my Ubisoft Uplay games installed on them, (splinter cell and Farcry 3 at the moment) My OCZ 90gb ssd will go into my sisters PC, with a fresh install of windows 7
Asus Pheobus Sound card for £100
sennheiser HD598 headphones brand new cost me £130, however they go for £200.
Long story short, the money was going to go on a PS4, however I came to a conclusion I have a baddass gaming PC, and All the games I like are on PC/will come to PC, (with a few exceptions of course like infamous) So the money I will have spent on a PS4, I spent on my system. Will sell my PS4 when it comes for around £400-£500 on ebay with the recipt.
Oh I also forgot A 1080p 24 inch Acer LCD monitor for £120. Does the job, not the best color reproduction but its decent.
So My PC specs are
Intel i53570k
8GB ram
GTx 670 Power edition
Asus Phoebus Sound Card
3 SSD'z in total
1TB hard drive for storage.
Now only thing Im looking to upgrade is my GPU, which will be a 780 once the 800 cards get released. I think I have found the perfect system for my PC to last me atleast 5 years. Sell my current GPU then once nvidia release new line of GPU buy the flagship last gen GPU.
All of this happened in the space of 13 months, IF I ever decide to sell my PC, It will only be the MB, CPU, GPU, RAM, will keep the case, PSU, Hard drives e.t.c (may sell the 1TB with the system)