Good gaming PC under 450$?

I have what looks like a decent rig in mind and I want to know if there's anyway to improve it or if it's okay as is but keep it cheap so I can play dayz atleast medium settings and gmod cs. And Minecraft full settings but still keeping it under 450$?

CPU: AMD A6-5400K 3.6GHz Dual-Core Processor ($66.99 @ SuperBiiz)
Motherboard: MSI FM2-A75MA-E35 Micro ATX FM2 Motherboard ($53.99 @ Newegg)
Memory: G.Skill Ripjaws X Series 4GB (2 x 2GB) DDR3-1866 Memory ($39.99 @ Newegg)
Storage: Western Digital Caviar Blue 500GB 3.5" 7200RPM Internal Hard Drive ($53.98 @ Outlet PC)
Case: Rosewill FBM-01 MicroATX Mini Tower Case ($21.99 @ Newegg)
Power Supply: Corsair Builder 430W 80 PLUS Bronze Certified ATX12V Power Supply ($29.99 @ Newegg)
Optical Drive: LG GH24NS95 DVD/CD Writer ($14.99 @ Newegg)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($89.94 @ Outlet PC)
Total: $371.86

This comes out to only 371 but I'm willing to go up to 450.

PS: I was recently told by someone who's good with PCs that for a good one I should look between 550 to 600. If I need to I will accept that too.