The Tengwar Anduril is normally worth $20-40. They are pretty rare, though, and there aren't many people around who are into Tengwar and know the background of this card. That's why gauging the price is like a scrapshoot.
geekgee are totally overpricing their cards. But since their are virtually the only ones offering them, people start to believe that the cards are actually worth that price. Smart psychological tactics, but very tiresome for people (like me) who actually try and get enough Hunters block cards (et al.) to play with...
So, are reasonable price for the Anduril

would be $20-40, but it could be as low as $5 and there will always be those suckers or desperados who shell out $99 for it.