Just so you know, it's $78 for 6 game boards, 6 players, 5 smash bros characters, 4 mario kart 8 costumes, 6 daily Amiibo presents in Hyrule warriors, extras in Treasure Tracker, and more to come. For just Mario Party 10, this isn't a good deal, all included, though, it's not bad at all.
It's like Steve Jobs all over again. No, it wasn't just an "iPhone" in 2007, it was
a revolutionary mobile phone, a widescreen iPod with touch controls, and a breakthrough Internet communications device. See? That's THREE things and NOT ONE. I must be really stupid not to see the value in amiibo.
So let's go with that sales tactic of yours:
to get the most out of the 6 amiibo from the Super Mario wave, I need to have Smash Bros., Mario Kart 8, Hyrule Warriors, and Captain Toad in addition to Mario Party 10. Is that what you're saying? Except there's a huge problem right there in the first game you mentioned: Smash Bros. compatible amiibo will be locked to Smash Bros. and can't be used with Mario Party 10 as both games read from and write to the amiibo.
Therefore, I need to buy Mario, Luigi, Peach, Yoshi, and Bowser twice to play both games. That's $143 that I'll spend on amiibo now ((6 + 5) * $13 = $143). But hey, that's not a problem since I get not one, not two, not three, but FOUR awesome Mii racing suits in Mario Kart 8! Day has been saved! And I still get 6 daily useless treasure in a completely lackluster The Legend of Zelda musou game. Finally I can play hide and seek with Toad! That's great, adding a full 10 minutes of additional post-game content to a 2-hour game. Now I know what I'm missing out on if I don't buy amiibo.
PLUS, you don't have to buy them all. I'm just going to get Mario.
You're absolutely right. You stay happy with just Mario and never getting bored of the same single board you can play in if you play amiibo Party. Because having more boards is completely stupid unless you buy more amiibo, right? See, I was very interested in amiibo Party's gameplay, but I'm not buying 6 amiibo just to have a bit of variety in the only game mode that makes sense for a Mario Party title and may actually have a resemblance to the good Mario Party games of old. But I have a choice, just like you said, I don't have to buy them all. In fact I'm not going to buy a single one because I'm skipping Mario Party 10 altogether for these shenanigans.
P.S. I'm sorry for being so rude, I had a long day.