Help me figure out the value of my Mac Pro

Hi, i've got a MacPro 1,1 2x2.66 Ghz (2007)

4 GB of RAM and an ATI Radeon 4870 HD video card.

The machine is in excellent condition.

Could someone give me an accurate estimate on what i could get for it?

Thanks, Nick

How would i figure out if my computer is a Xeon 4-core Nehalem or not?

In about this mac it just says 2 x 2.66 GHz Dual-Core Intel Xeon

The computer was made in 2007

Wait, its a Xeon 4-core, nvmd