I bought mine for $475 and sold it for the same amount 2-3 years later. I saw one in "almost as nice" shape as mine about a year ago for $425. Probably should have bought it...but my M66 balances more naturally (for me).
The 586 is a beautiful, quality revolver. The blue of the 586 is far more classy than (and not nearly as common as) the stainless 686.
If the price is right, and the condition is good, and it speaks to you...go for it.