i wasnt able to read the PDF very well so i couldnt tell what what inboard graphics there was.
On page 16 of 50 in the PDF it lists the graphics details. 3 of the 4 models had optional
dedicated graphics cards. All of the models have Intel integrated HD graphics of some form. I would not expect your machine to come with the optional dedicated graphics card if it is a great price. Does it say on overstock.com?
i was going to put my nvidia 750 geforce from current machine into the new one.
Page 21 of 50 lists the power supplies for each of the models (MT, DT, SFF, USFF). Assuming you are looking at the 240 watt model as you've said, that would be the SFF model. According to page 19 of 50 that model supports a max of 50 watts
from the PCIex16 slot. Assuming this ( http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-750/specifications
) is your card, it recommends the system have a minimum 300 watt power supply, and be able to provide 55 watts to the graphics card
. Also, I've no idea if your card is fullsize or low profile, but the SFF model is for low profile graphics cards, not full size cards.
Get a different computer, if possible with a power supply that exceeds your minimum power requirements, as gaming is power intensive.