It all depends if you are a fan of Castlevania. But I would imagine if you were, you've already got the PSP Dracula X Chronicles which includes the game. So you just have to ask if you really want it to play on your console. Really I think CV Dracula X has been overpriced for ages. Yes, it's a good game. It has an amazing soundtrack. But $100+ range really? Even now after anyone can pick it up for the PSP for like $30?
So it's all up to if you think it is worth it. I'm a pretty big fan of Castlevania. I really enjoyed CV DX on the PCE. I'd buy it if I felt that I had the money to spend, but probably only after many other things I'd want to purchase. Afterall, being real you can play the game other ways now. You'd be paying quite alot of money to have the real deal. With that same money, couldn't you get a number of other things, games, that you also want to get?
So really no one can help you make the decision. Unless you're just asking if they think as the market goes if that is a good price for the game or not.
I'd certainly buy it for $55!