I wouldn't buy it. I've had a similar system (Pentium D - 3.4GHz, HD5450. It ran Warband on Medium-Low.. about 20-24 fps)
I'm guessing you have a tight budget?
Also, if you're looking to build a new system that is a bit cheaper, I would recommend going with a AMD APU based system. They're cheap and will save you from buying a graphics card.
I'm not very good at this stuff so my knowledge is very limited. Hope I helped.