Do you buy gear new, used, both?

Exclusively used! And preferably broken. defective, or malfunctioning.

My gear is a mix of new, used and demo. 
 

Most of the new gear I have bought has been home theater-related, because HT technology ages like milk. The rest of it, other than stuff I bought new 40 years ago, has all been bought used, most of it lying fallow right now, out of the rotation—a couple of Sansui stacks, some HK, Denon, and Yamaha amps. I just sold my primary speakers and amp—NHT 3.3s and a Rotel RB-1090 (my wife and I are 'down-sizing.') It hurt less than you might think, because I had enjoyed them for a long time, and sold them to friends.

As far as buying used goes, the thrill of the hunt, and sometimes bagging an elephant, is what keeps me involved in the hobby. Isn't it great? Enjoy!

A mix of both. But only late model used. 

Both. A fun part of this hobby for me is adding and upgrading equipment over time.  I’ve bought new, used, demos and open-box equipment.  Always looking for the next deal.  Buy for myself or for family and friends.  Also enjoy selling used gear or giving it to family and friends.