Build a new pc or upgrade current?

[wipeemouthd]

My current build is as follows -
Alienware x51
3rd Generation Intel® Core™ i5-3330 (6M Cache, up to 3.0 GHz)
Windows® 7 Home Premium, 64Bit, English
8GB2 Dual Channel DDR3 SDRAM at 1600MHz
1TB SATA 3Gb/s (7,200RPM) 32MB Cache
NVIDIA® GeForce® GT 640 1GB GDDR5

I am not so happy with my pc anymore and I'd like to have more power, but the thing is, I'm not sure if I should build a new pc or upgrade this. I am faced with the problem of a small case. I do not have enough room to add any larger GPUs and there isn't a lot of room for change. I have some help getting parts together for this build - http://pcpartpicker.com/p/14xmf . I am not sure if I should just get a new case and upgrade, or build an entirely new pc. I feel like I'd be upgrading pretty much everything besides the motherboard and the CD drive. If you think that I should just upgrade my current pc, could you recommend a case, gpu, cooling, and cpu or let me know if the ones on pcpartpicker are good.

Thanks for reading, I hope this wasn't too confusing.

- Mark

Edit - I am on somewhat of a budget, so please do not list items that are insane. I am just looking to have a gaming pc that can record games well and play games like Metro: Last light on higher than "low" settings

 

[envy14tpe]

I would salvage what you have. Keep the i5-3330 (maybe upgrade in a year or two), you got good RAM and HDD. Also, WIndows 7 is on the HDD.

What about mobo?

I'd buy these parts. The case is on SALE until today. It's a $100 case for way cheaper. It will allow you to upgrade in the future.
Also, the GPU will play all games on High if not better settings.

PCPartPicker part list / Price breakdown by merchant / Benchmarks

Video Card: Sapphire Radeon HD 7870 XT 2GB Video Card ($248.98 @ Newegg)
Case: Corsair 500R Black ATX Mid Tower Case ($69.99 @ Newegg)
Power Supply: XFX 550W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($54.99 @ NCIX US)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($16.99 @ Newegg)
Keyboard: Razer BlackWidow Tournament Edition Wired Gaming Keyboard ($69.99 @ Amazon)
Mouse: Razer DeathAdder Wired Laser Mouse ($59.99 @ NCIX US)
Total: $520.93
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-06-12 02:36 EDT-0400)

 

[swifty_morgan]

so, get a larger case. buy the card you want and add the PS you also have listed if your old one won't supply enough power. the cpu you have should be fine for a while.

 

[envy14tpe]

The real issue with the Alienware X51 is the GPU. It has a weak GPU, once you have enough power (PSU) and a faster GPU you will be amazed at how much better games can be.

 

[spat55]

I'd get something not Razer, I have a mouse which is good from them but you can get products as good as theirs for less, as it is the brand your paying more for than anything else.