Upgrade or Build a PC?

[HungryJ]

I'm kinda new to the whole building a PC thing and just like to ask a question. I'm wondering if it be cheaper and worth it to upgrade my current PC, or just build one. I'm looking to upgrade the graphics card for sure to play games like Skyrim or Fallout 4 at least med-high setting.

My current PC is an HP and the specs are:

Operating System-Windows 8.1 64-bit

CPU-Intel Core i5 3450 @ 3.10GHz Ivy Bridge 22nm Technology

RAM-8.00GB Dual-Channel DDR3 @ 798MHz

Motherboard-Foxconn 2ADA

Graphics Card-1024MB ATI AMD Radeon HD 7450 (MSI)

Storage-1863GB Seagate ST2000DM001-9YN164 (SATA)

Optical Drives-hp DVD RW AD-7290HR

Audio-AMD High Definition Audio Device

Power Supply-300W

Since I am new to this I'm not sure if the HP is a lost cause or if there's some parts in there that make it worth upgrading. If I need to build a PC my budget would be around $700(USD). Thanks for reading and hope to learn a thing or two.

 

[jollypirate]

You can just upgrade the graphics card and psu for now, the cpu is a bit older but it is still good for games. With your budget you can get a gtx 970/r9 390 and a good psu, and you would still have 300$ left with which you can get an ssd.
http://pcpartpicker.com/p/szPXzy
You would be able to play every game on high/ultra settings at 1080p

 

[HungryJ]

You can just upgrade the graphics card and psu for now, the cpu is a bit older but it is still good for games. With your budget you can get a gtx 970/r9 390 and a good psu, and you would still have 300$ left with which you can get an ssd.
http://pcpartpicker.com/p/szPXzy
You would be able to play every game on high/ultra settings at 1080p

Thanks I'll look to upgrade to an SSD in the near future. I've decided on an GTX 960, just a little more affordable at the moment seeing the Canadian dollar is shit. Thanks again I appreciate the help.