Here is one on ebay that is cheaper than the one you saw. Hope This helps.
http://cgi.ebay.com/ebaymotors/20-inch-Cadillac-escallade-silverado-OEM-original-GM_W0QQcmdZViewItemQQcategoryZ43960QQihZ007QQitemZ170108166580QQrdZ1QQsspagenameZWD1V
Hey, do you know the offset on these wheels? would they tuck on a Hardbody Nissan? Would probably need to be a +30 or better I imagine. Maybe even +40.