I do shoot CAS, I have one Montado in 45 LC. The gun is legal in and was designed for, mounted CAS, but the hammer configuration and the grooved grip frame that make it so nice for mounted make it illegal for us ground shooters. I have one just because. It is a fine handling gun, mine is stainless, I do shoot a bunch of black powder cartriges through mine. Davidson's (galleryofguns.com) is, I believe, the major distributer of the guns, they used to bring about $100 more than the new model Vaquero that they are based on, I would think your $425 should be a decent price. Mine shoots fine at CAS distances, never put it on paper yet.
Have fun!
MDJ