Utah Red Horn Coral has become one of those rocks where prices have shot to the stratosphere. This happens when the supply dries up and people want some anyway. Someone at the mega-site Etsy thinks that a single coral of a similar size is worth just less than $1,000.00. Other sites selling Utah Red Horn Coral have been linked below. I have a very limited supply and I want to continue to offer a piece now and then so I don't list it all the time.
 
Even corals from the Utah site are often white, colorless material rather than beautiful red agate. You can still find smaller pieces at Ebay and even at the original dig site. A large display specimen featuring mixed red and white and a polished red agate layer has been listed here at a lower price. But if you're looking for a premium, large piece, good enough to turn into unique jewelry, this is your rock. You're not likely to find one of this quality anywhere else.
 
https://www.etsy.com/listing/1099772629/red-horn-coral-fossil-museum-quality
 
https://www.mineralauctions.com/items/red-horn-coral-classic-material-87357
The winning bid at auction for this coral was $368 but it's only 2.7 cm in diameter and totally encased in limestone. Hopefully, the auction page is still there to see.
 
My dad had a role in opening up the site in the foothills of the Uinta Mountains of Utah more than half a century ago. You can read all about that in a blog essay here:
 
Utah Red Horn Coral
 
A much more recent video shows you what rockhounding the site today is like:
 
Rockhounding Utah Red Horn Coral Today
 
The best information I can find on the web is that the dig site has been closed for quite a few years now.