He maybe selling it because he hauls large loads......I bought a tire carrier from the wreckers for 50 bucks CND, but never ended up installing it because I couldn't fit the bracket in there without cutting the sheet metal. The pins were rusted solid, so I drilled them out and put bolts on (the bottom one should have been put on upside down... DOH!! pssd) But the longer I've had the truck, the more I find I'm hauling long stuff that requires me to tie down the liftgate. If I had the carrier on there, I would never be able to haul it. ( I really don't want a spare tire carrier flopping around back there.) I don't have a roof rack, so strapping things to the top wasn't appealling to me, and it always happened to be weird odd shaped things. I will one day put a roof rack on there, but I may do it to put the tire up there instead. It seems like less work to me to install a roof rack then installling those upper brackets. And to my knowledge of this board, nobody has attempted the bottom brackets yet, if it's even possible, (forgive me if it has been done). I started surfing this board about year ago, and was very interested in what was happening with the spare tire carrier situation. There is a lot of options, like fabbing up a rear bumper with one attached, or not being afraid to cut into some sheet metal to installl the OEM one. But one thing is for sure, there doesn't seem to be an easy solution. Good Luck!
P.S. I've got one sitting in my garage if any one's interested, but I've only got the top brackets, and one is jammed up above my tail light at the moment, (a story I don't want to get into right now)