A $1000 photo had better tell a very interesting story. I have yet to see a single photo that I would shell out that kind of cash for strictly on the basis of artistic merit.
Especially nowadays, with near-global access to the "tools of the trade" that allow for advanced photography and post-processing, the value of aesthetic work, in my own eyes, has declined substantially. In truth, it's largely a matter of simple economics...supply and demand. At one time in the not-so-distant past, seeing a Dragan photo, for example, would have been remarkable. Today, anyone with a pirated copy of Photoshop and access to Google can produce a near-perfect replica.
The exclusivity of pretty pictures doesn't really exist anymore. But, at the same time, with the prevalence of digital cameras and our flood of media photographers, just pressing the shutter release at the appropriate time to capture a significant event isn't really all that impressive either. For $1000, I would demand a mix of both aesthetics and historical importance. As an example, I was browsing through Getty's shots from Bhutto's assassination yesterday, and none of them are worth $1000 because the key photos (of the moment before the shots were fired and of the following explosion) were out of focus and showed no sign of composition. Sure, it's a little demanding, but that's just the way it is anymore.