I'd list it for $1000 if I didn't need to move it quickly and I'd be prepared to come down significantly off that figure. $2000 is an extremely difficult sell when you can build a similarly performing rig new for around $1100-$1200. And unless you're an actual company selling assembled PCs, the moment you took these components out of the box, you lost a third of the resale value right then and there, almost three years ago.
Realistically, if you can't find the perfect seller, I'd expect you to get $800 or so in the end.