Definitely not all of them. I don't even want them for their intended purpose, not in SSB anyway. The whole "training partner Lv.50 CPU spectator mode" thing doesn't interest me enough to spend money to do so.
I am only going to buy ones of characters I like, and more importantly, figures that I like.
We've only seen 14 so far, and of those, I definitely want Zelda & Link. I like Wii Fit Trainer, Kirby, Villager, Marth & Peach, but I am probably not going to buy all of them.
And even then, I may hold out on Marth & Link to get Toon Link and Lucina instead.
Additionally, I want Luigi, Zero Suit Samus, Olimar, Little Mac, and I'm undecided on Greninja, Robin & 3rd parties. I feel like Greninja's unnecessary, because if I REALLY want a figure of him to display, I could get a cheaper one from Tomy, and still be good quality (unlike the 3rd parties).
But like I said, this is all dependent on various things. Mostly price, but also, the ones I will get the most out of.
So, like, I will narrow down the ones I want to characters I actually like, but after that, most likely narrowed down to characters who I can actually use across multiple games and characters that I can't just get another figure of elsewhere.
There's also the fact that non-SSB figures will come out. So maybe there will be a Death Stare Luigi MK8 figure, or a Link based on the new Zelda U. It all depends. So yeah, I really don't know who I will be getting, or even when. Since there are simply too many factors. I may not get any at first until I know what's going down.