Someone mentioned getting WH2O because GB would be available for a while, but that wasn't your question. Go GB. Here's why: much more challenging game, already much deeper than WH2O (and likely to have code updates).

Here's the other reason, WH2O will also be available for a long time, just on the used market already. I had WH2O for a few months but was pretty much done with it after about two. My taste, but it got old quickly. Fast and fun, but very limited feel and the theme, while original, is just so-so (though it is a fantastic realization of a theme).

I'm with Neo. I think on machines I want that keep ballooning, I'll wait for that just right situation. If it doesn't come, no biggie, most every pin I want to play I know someone that owns it within a few hours drive. Otherwise I'll do what I did in the past and buy a game that was in fine shape but already to the high end of the market to where I took a lost to move it so I could get something else.

I would not pay $5K for WH2O, even in fantastic condition, but that's me. I wouldn't turn one down again but I see it closer to 2500 (for me).

Still going with GB. WH2O is fun for a hot minute and always feels smooth but gets stale. I think GB will challenge you shot wise longer.