PCPartPicker part list:
http://pcpartpicker.com/p/LZ9TTW
Price breakdown by merchant: http://pcpartpicker.com/p/LZ9TTW/by_merchant/
CPU: Intel Core i7-4770 3.4GHz Quad-Core Processor ($294.99 @ SuperBiiz)
Storage: Samsung 840 EVO 120GB 2.5" Solid State Drive ($99.98 @ OutletPC)
Video Card: Zotac GeForce GTX 750 Ti 2GB Video Card ($129.99 @ SuperBiiz)
Power Supply: Corsair CX 500W 80+ Bronze Certified Semi-Modular ATX Power Supply ($34.99 @ Newegg)
Total: $559.95
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-06-11 23:36 EDT-0400
He is just upgrading his CPU, graphics card, and his PSU. He is also adding an SSD to his computer. He has 8GB of RAM already already installed