Youre not casting a spell but activating an ability, Amphin Mutineer is not entering from the graveyard so neither of these cards will stop you
More than anything, these moments seem to be self-perpetuating, where everyone gets tremendously excited about one particular card, which creates demand, which raises the price, which exaggerates the rarity, which creates demand The next most expensive right now is the Latias ex at almost $200, then the gold card version of the Pikachu ex at $100, and that Hydreigon pictured above at about $95
The red Final Fantasy land, however, might be good enough to see some play, but players are unlikely to use it in the traditional sense
If you're worried about losing a somewhat more vulnerable source for doubling your tokens, don't worry
This ends up being all fine though for one reason: Kuribandit provides massive amount of setup for the deck and digs for Spell cards