The Cowboy Limiteds came out around 1996. The first ones had checkered stocks and 24" barrels. Around 2002-2003 they had smooth stocks and 24" barrels, then maybe 2005 they had smooth stocks and 20" barrels. The last ones were made in 2009 as Remington was taking over.
There is a big demand for the earlier 24" barrel guns, they were made for fewer years so they bring bigger bucks. I see more of the 24" guns in 45Colt and 44Mag, less in 357Mag. The price is high, but not within reason, some have sold for that. The seller is just trying to get the most he can. Take a look on Gunbroker sometime. I have bought and sold 5 or 6 of them in the past two years and they will bring high prices. I have gotten lucky a few times at gunshows and found them for $600-700, but that is rare.
All you can do is make him an offer, if he won't take it you'll have to keep looking. I think $900-1000 is more realistic, $1300 would be top end for a virtually new one. The last one I sold was a couple weeks ago, it was nice but not great, I sold it for $925 shipped.
Hope this helps, good luck.