I also recycle USPSA targets after matches. I hang paper plates, index cards, copy paper or targets printed on 8.5"X11" paper on them. My guess is printing a few targets is preferred by those people with access to a laser printer/copier and a boss who frequently leaves the office.
Have ordered silhouettes from U.S. Targets that are great at about .15 per, in quanties. Also used TargetZ.com and Target.WS and printed my own. Between the three, that's about all I've been using.