Smith & Wesson 500 Revolver.?

I don't own a gun, i have shot a few. I am in love with the S&W 500 Revolver the one with the extra large frame. What do you think about this gun? Should i start out small, or is this a good first gun? What is the price range, bullets too? If you have experience with this hand cannon tell me about it. I think there is two different models, the standard compensator and interchangable compensator, what is that and whats the difference.