Very simply, you can get an Epson 5010 for $2000 NEW and it is the same projector as the Epson 6010. The insides are identical. The differences are the 6010 comes with a black case, spare bulb, ceiling mount, and an extra year warranty. If I left anything out, someone will let me know.
So you are basically paying $100 for a used projector to get an extra bulb and an extra year warranty, when you could just get a new one for $100 less without the new bulb and extra warranty and what not...
Then as Mike noted, you can get a JVC B-stock for less than that. Though if your end-result viewing is tied to keeping some lights on in the room, I'd say the Epson is the better choice over a JVC.
That said, except for the ambient light issue:
I can tell you first hand that if you are not going to be doing a lot of 3D, the JVC is the better projector over the Epson. Why is it better?
Well, it's more feature rich with motorized focus, lens shift, and most samples are sharper than the Epson (despite what some Pro reviews claim).
The JVC also has a higher pixel fill which results in a more film-like image, plus it does better blacks even without an IRIS, which means in films things look smoother in dark scenes and less inconsistent.
The build quality is better as well IMO. LCOS has semi-sealed optics and is less likely to get a dust blob.
The only three areas the Epson beats the JVC that most would notice would likely be:
1) Color Accuracy, though you need to calibrate the Epson if possible
2) 3D Ghosting - The Epson produces a cleaner 3D image.
3) Ambient Viewing Brightness - The Epson is brighter than the JVC in the Epson's torch mode, but the JVC is brighter than the Epson if they are both in their most color-accurate modes.
I am not saying the Epson is a bad projector, it's not, but it's not the best you can do in this price range if your main focus is movies (and I dare say with some Sports even). I think the JVC's speciality isn't Sports, but it still does fine. The problem with you buying the JVC is the torch mode isn't there like the Epson has.