The game is quite rare, just not hot. There is not a big market for it, but it is not common. Others include:
Way of the Samurai 2
Echo Night Beyond
Bujingai
RAD
This is typical of games with low-preorders. The initial print run is the only run, so usually there is no overstock. Demand may be core and niche, and strong, but not in numbers to justify high prices.
Games like Intelligent Qube, Poy Poy, and Puzzle Bobble, on the PS1 are evidence of this trend in the last gen