Ahaha, I found it particularly entertaining that they have a 300w in a FX8120 + 6670 but a 700w in a FX4100 + 7750.
That said I would probably grab the 7750 instead of the 8120. unless you werent opposed to spending to upgrade the GPU and PSU.
But that kinda defeats the purpose of buying a prebuilt...
Went through the rest of ibuypowers lineup and some of them are just ridiculous. This one is exactly the same but has a 2gb card instead of 1gb and is 130 bucks more: http://www.newegg.com/Product/Product.aspx?Item=N82E16883229395