Well I won't comment on the Mac Pro itself, but I see the 24" Cinema Displays going for $500 on my local craigslist.What do you think would be a fair price for this:
Mac Pro 2009
Quad-core 2,66 Ghz
16 GB Ram
Radeon HD 4870 512 MB
2,6 TB HD
OS X Lion & Windows 7 Ultimate
Apple LED Cinema Display 24"
The value of a used display hinges heavily on hours/type of use. Obviously Apple displays don't track these things. Some other displays do. Anyway there's a gradual shift in the gamut which is normal. The maximum brightness degrades over time which is also normal. With Apple displays in my own experience, after a couple years they look nothing like a new display, but if it's held up well, people do pay for them.Well I won't comment on the Mac Pro itself, but I see the 24" Cinema Displays going for $500 on my local craigslist.
In general, including the original box and software will help your price.
The price you paid means nothing, because when you bought it, ram was much more expensive, and a decent 24" display cost a lot more. You need to keep these things in perspective. Now you can look at what Apple charges for a refurb 2009 today including warranty. It's around $2000 in the US. This is without a display and with base ram, although you can pick up third party ram to 16GB with a long warranty on the ram for around $100. With the display it depends on condition, which would vary by usage pattern. Displays lose brightness with time and their gamut tends to shift.No one?!
If it can help, when it was bought it cost around 5000