I'd pay up to 150 dollars, not more.
That's still a kind of hellish price for a game. (Not counting shipping).
Even some Neo-Geo carts are cheaper.
100 € would be the higher price I would pay. Even after finishing it I'm still ready to play it for hours as I would if I got it for the first time.
Or 150 € for a pack : Rondo of Blood (TG16) and Nocturne in the Moonlight (Saturn) (I'm still looking forward to play as Maria).