They actually are going for about $150. And not just one or two.

http://www.ebay.com/csc/i.html?LH_Complete=1&_trkparms=65%253A13%257C66%253A2%257C39%253A1&rt=nc&_nkw=radeon+hd+5870&_dmd=1&_dmpt=PCC_Video_TV_Cards&_sticky=1&_trksid=p3286.c0.m14&_sop=15&_sc=1