I have been thinking about getting a revolver to carry occasionally. I have a SP 101 that I like, but I think of it as more of a back up gun than a primary. I have been looking at the colt python's and king cobra's on gun broker. They look very nice, but they are also very expensive. Why do these paticular revolvers demand such a high price? And are they worth it? How much should someone expect to pay for these revolvers in about NIB condition?