Do you understand how supply and demand works?
If usedcars.com went into auction, everyone on this forum would get in on it and the price would shoot up accordingly, probably to 6 figures.
If usedcars.live went to auction, maybe 4 people on earth, all being nTLD speculators, would bid on it. Then the winner would post it in the nTLD showcase forum and they'd all say "great buy! Hold for 5-10 until the value hits $xx,xxx!". A year later, it would fall to an expiring auction.
If used.cars, one of the few nTLD domains that is great and makes sense went to auction...oh wait, it's reserved by the registry. So, if there was a big money buyer, the registry would get the sale, and one of you speculators would post the sale on namepros claiming how great it is for new extensions, meanwhile none of you even had access to that caliber name in the first place.
The reason .com does so well in the aftermarket, outside of it being the obvious staple of the internet, is because all .coms were available at the same price since the beginning of the internet, and buyers are able to dictate the value.