If I were looking at a used one its price would depend first of all on age (lamp hours), and how well it is converged. Values plummet on big ticket items like these due to lack of warranty and other causes. Price will depend on buyer of course but I'd expect below 50% of original price (not necessarily MSRP) typical, depending on details, and history. Because these are sold regularly heavily discounted new, you have to compare street prices of a new unit and work down from there. If I were buying Steve's (and not his imposter LOL), or Rivercitylad's where I know the person and the history, it would bring a much better price than from a stranger on Audio/Videogon where I know nothing about the unit, how it may have been cared for, etc. Or if I were buying one perfectly converged and freshly serviced at Sim2, that would be a very good one for example.
Short answer, it depends
. And Steve, I'll give $2k for yours if it helps
That said, I'd take a used C3X over some alternatives. But I love 3 chip DLP