This PC was originally built in 2010.
AMD Phenom II x4 955 Black Edition Asrock M3A770DE motherboard (sb7xx based) 2x2gb DDR1333 Radeon HD 5770
Since then I've made some minor updates to the system over the last 3 years, originally the system hard disk was the 500GB WD green in the parts list, I moved to a Spinpoint F3 and relegated the WD Green to a backup disk. I had an additional WD Green from another system that I salvaged for use with Windows 8's File History feature.
In April I switched out the original PSU, an Antec Earthwatts 430D for the Seasonic X750 Gold (closest I could find was 760 on here)
In late June I moved to replaced the GPU with the 7870 below, I found that the Phenom II was bottlenecking the 7870 significantly so I moved to a Haswell chip.
The case I have had since I was in 8th grade. At one point I had 4 of these (2 were the previous generation model), I now only have this one and another just like it. For some reason I can't bring myself to part with this case. I actually built the PC in a different case in 2010 and decided to move it over to this one that was sitting in a closet at that time.
The cost below is not accurate.
Edit: Also, thanks to auxy from ##hardware on Freenode for helping me identify the bottleneck