I practically only buy used gear. There are not may high end stores where I live, their selection is narrow and they charge exorbitant prices. I never bought speakers used, but I did buy a number of headphones. It is very difficult to find a place that would let you listen to headphones (Japan has no issues with that... but US does). But used or demo units provide great opportunity for evaluation. If you don't like them, you won't lose much.
Exception is when technology is new and there are no used units yet. For example, I purchased R2R DAC new - Denafrips makes really good ones and you rarely can find them used (I guess people keep them).
Otherwise I bought and sold Pass, BAT, Sonic Frontiers, Adcom, Rotel, Marantz, Auralic, Rega, VPI, you name it.