I'm no longer surprised we underestimate the cost of things that we would like to have. Is $6K out of line? I don't think so AT's Habitat and Ursa Minors top for JK Wranglers are close to that. Somewhere I have a link to a French company that makes a pop-top for 80 & 100 Series LC and those are close to this price or for that matter the the price of Dormobile roof. If you want sticker shock, price out the pop-top roofs for LC manufactured by several German companies.
$6K may not be affordable or justifiable based on anticipated use, but that doesn't mean its too expensive.
Jim