It's got "Extraction" in the title and the other versions don't. That's worth $20, isn't it? Besides, people interested in it are going to be people who liked the original. They'll be informed.
The biggest drawback, in my opinion, is that people who played the original, played it in HD. Are they going to be satisfied with a Wii game? It's a game that they loved, on a different console, with weaker graphics, and 100% totally different gameplay. That's like Pikmin being released as an FPS on the 360!