The power you need is mostly determined by the vga card. Without upgrading the vga card you will be OK.
There is little sense in upgrading the vga card unless it is a couple of tiers better, like to a GTX260-212. Such a card wants a psu capable of 36 amps on the 12v lines, and your psu is marginal for that. The wattage is ok, but the amps may not be, they do not specify that, which is not a good sign.
Raidmax is considered a tier 5 unit on this list: http://www.eggxpert.com/forums/thread/323050.aspx
For $45 you really should not expect much.