I just checked eBay and found a couple CIB that went for $115 and $150, which is still crazy high. But I understand how a later HuCard game like that can demand a premium when its CIB(the kind that don't have jewel cases) and good condition.
I wonder if the lone HuCard would sell for any more than $50 still.
Anyways, if you're looking to buy one, the HuCard is definately way cheaper than the CD version, which only adds CD music.
If you don't already own a PC Engine, you should buy one and the japanese HuCard game. Together they'd cost less that the U.S, HuCard CIB.
If you really want to save some money down the road, you should invest in a PC Engine Duo system. Then you can play all JP Hu's, all CD2 & SCD games, and will only need an Arcade Card Duo without converter to play ACD games.
And if you ever have it modded, it'd still cost lest total than a U.S. Turbo Duo.