With out more info I would say $225-275.
vista still cost like $90
Amd quad core $90+
6gb Ram (assuming ddr3) $70+
500+gb harddive $60+
*note those are new item prices not used*
useful info would be:
Cpu model/speed
Ram type/brand (ddr1/2/3)
Is there any type of add on cards video/sound/wifi cards
Any type of transferable warranty
/edit
Star Wars: The Old Republic requires a video card that has a minimum of 256MB of on-board RAM as well as support for Shader 3.0 or better. Examples include:
ATI X1800 or better
nVidia 7800 or better
Intel 4100 Integrated Graphics or better
so it has
atlest a $50ish video card?