I don't think I've ever noticed anyone wearing the same outfit multiple times. I couldn't tell you what any of my coworkers are wearing today, because it's been over 10 minutes since I looked away from my screen. I'm assuming people do reuse their clothes though. I know I don't throw them away after wearing them exactly once.

My old boss is an exception - she had a different outfit for every day, and every single one of them looked like it'd taken more consideration to put together than I've ever put into clothing. So when she wore the same thing again sometime later, it was noticeable only because you were already conditioned to expect something new every day. Never heard anyone make a comment about repetition though - only compliments about the styles.