You CAN, but it's probably not the best idea. It would make a lot more sense to use the money to get a better PSU first, then save up for the graphics card. But it will certainly probably run it. Like I said, it might not last long though, and then you'll have to get another PSU anyhow, and maybe another graphics card, motherboard, cpu, etc., if the power supply has a catastrophic failure and takes them all out with it.
That's not a very demanding graphics card, so it might be ok for a while, but it's also a pretty terrible power supply, so I'd be really worried about my hardware even without adding the graphics card to the equation.