Gaming System Check-Up

Hi, I'm planning on purchasing a new computer build primarily for gaming that will be still viable with upgrades in the future. Hoping to get some tips on improvements (budget, performance, redundancies etc) before I order everything. This is a complete new system build meaning I'll be ordering everything including monitor, speakers, etc. Thanks!
Note: I'm mainly looking for improvements in terms of cost, trying to reduce the price without sacrificing too much performance.

Main System:
MB
GIGABYTE GA-MA770T-UD3P AM3 AMD 770 ATX AMD Motherboard - Retail

RAM
G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10600) Dual Channel Kit Desktop Memory Model F3-10600CL9D-4GBNT - Retail
CPU
AMD Phenom II X4 945 Deneb 3.0GHz Socket AM3 95W Quad-Core Processor Model HDX945WFGIBOX - Retail

GFX
SAPPHIRE 100279-1GL Radeon HD 4870 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail

PSU
APEVIA ATX-JV650W 650W ATX12V / EPS12V SLI Ready CrossFire Ready Power Supply - Retail

HDD
Western Digital Caviar Blue WD3200AAJS 320GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive

CDD
LG 22X DVD Burner - Bulk Black SATA Model GH22LS50 LightScribe Support - OEM

CPU Cooling
COOLER MASTER RR-CCH-P912-GP 92mm Sleeve CPU Cooler - Retail


Accessories, etc
Monitor
ASUS VH202T Black 20" 5ms Widescreen LCD Monitor - Retail

Keyboard & Mouse
Saitek PZ30AUR Red USB Wired Slim Eclipse Keyboard - Retail

Logitech G7 Black 6 Buttons Tilt Wheel Cordless Laser Mouse - Retail

Speakers
Logitech S-220 17 Watts 2.1 Multimedia Speaker System - OEM

Computer Case
Antec Three Hundred Illusion Black Steel ATX Mid Tower Computer Case - Retail