I know that the Wave can get you in that Prophet X territory (up to some point), but you’ll feel like it isn’t exactly something that would be sufficient to make you forget the Prophet. I’m not saying go for the Prophet either, but just don’t get the Wave just for getting it.
I also know that the Wave is kind of rare, but I think that 2K is a lot for what it is and how old it is. I wouldn’t invest my money on it. You already have a lot of nice things, and maybe, just maybe, you should start thinking about getting rid of stuff you don’t actually use/need. The 2K you’d spend on this Nord + money from your Kronos, you could achieve the price tag of what you actually want.
Unless the Nord Wave is something you really want to use, even if just out of curiosity, go for it. If you’re trying to use it as a substitute for something else, run from it. Expensive!