Wow, what a douche that one seller is. Insulting your bidders AND admitting to hoarding the game? If I was in the market for a US Dynastic Hero, I'd have too much self-respect to degrade myself by bidding on an auction that basically says "you're an idiot if you bid on this". I hope his copy sells for the lowest amount of the three.
Anyway, that's surprising to see three up at once. Maybe they all want to cash in after seeing that $560 copy that sold?
I love Dynastic Hero, and while it would be really cool to own the US release, I'm happy with my Japanese copy and the Virtual Console release of the English version. It's very easy to play in Japanese, even without knowing the language (and there are FAQs available for anyone who does get stuck), and to be honest, having recently played through the VC release, playing in English doesn't add much to the experience. There isn't much of a story beyond what you can pick up playing it in Japanese, and the localization is pretty awful with loads of mistakes (I think my favorite is when a NPC says "Oh on" instead of "Oh no"). And, of course, there's the Genesis version of the game available in English too.
But I imagine most people in the market for the US Turbo Duo release are just collectors and don't care as much about playing the game as simply getting a complete set of Turbo CD releases.