See bro, if you absolutely CAN NOT spend more, then i guess you got no other option than the Saga II 500W.
If you can find one, get the CX400 not the CX430, will set you back around Rs2800 approx.
I had my rig on the CM extreme 600W for a few months,nothing really went wrong, so I am pretty sure nothing will really go wrong in your case too.