well hey dude! Since we are from the same country, I might as well help you out. You said you have $400(something like Php20000).
you can have a decent rig, but that's just the cpu by the way.
processor; corei3-3220 - php5400
Gpu: hd7770 - Php6000
RAM: kingston 4gb ddr3 1333 - Php800
Mobo: Gigabyte GA-B75M-D3V - -Php 3050
You go problem the other parts you would like to go with your hearts content.
the prices are at the time of writing.
trust me, that rig stated above can run modern games at 50-60fps 1080p med-highest
good luck searching the other parts