I am just getting back into the game and everything has changed from when I sold stereos to work my way through college in the early 70s. In the last six months, over the internet, I have purchased B&W Matrix 803, B&W CDM2, JM Lab Electra 906, Velodyne SLP-1200, Revel Performa F50 & C50, all used. We are happy with all of the purchases: It even makes my wife happy to argue over which one sounds better. My wife likes the JM Labs & Velodyne SLP-1200 better than the Revels. If she were not watching me type this, I would tell you she is wrong.
Research it first. If you buy it used and do not like it, sell it. If you buy it right, your loss should be minimal. It certainly gives you access to speakers otherwise unavailable.