In particular, one of the CE models. I'd prefer the 24 fret, tremolo. But in general, how much do these typically run used? Can one be had for under a grand? And for that matter, how much can you get them new?
A new one will typically set you back ~$1500. Music Gear Guys is blowing 'em out and you might be able to get a sweet deal.
Used CEs frequently go for under a grand on eBay and can be sometimes be found for under $900. You might also check around the Birds and Moons forum--lotsa PRS junkies (including myself) hang out there.
Ebay is a good indicator of a guitar's real worth. Just type in PRS in electric guitars, then sort from highest to lowest. My preference is for McCarties, so I hope to see them used for $1200-$1500 when I search for them.