Upgrade cimputer - need help!

[Chriasp]

Upgrade computer - need help!

Hey I would like to upgrade my computer so I could run WoW on 120 FPS on Good/High/Ultra WITH Tyrael and Tuanha running.

My specs so far is:

Intel(R) Core(TM) i5-3350P CPU @ 3.10GHz
16 GB DDR3 Ram
GeForce GTX 550 Ti 1gb

Operating System
Windows 7 Home Premium 64-bit SP1

CPU
Intel Core i5 3350P @ 3.10GHz
Ivy Bridge 22nm Technology

RAM
16,0GB Dual-Channel DDR3 @ 532MHz (7-7-7-20)

Motherboard
ASRock H61M-DGS (CPUSocket)

Graphics
SyncMaster (1680x1050@60Hz)
1023MB NVIDIA GeForce GTX 550 Ti (EVGA)

Storage
465GB Western Digital WDC WD5000AAKS-65YGA0 ATA Device (SATA)
Optical Drives
ASUS DRW-24B1ST c ATA Device

Audio
Realtek High Definition Audio


What is the bottleneck here ? And make it as Cheap as possible, I am just a poor student. Do I need to Upgrade ALOT or is a few components enough?

Thanks for the help.