SNAPE KILLS DUMBLEDORE
Oops. Little late for that.
And just who would actually bother, or have enough money to afford Yojimbo at this time?
Additionally, the requirements for Zanmato are deathly steep. Imagine the most money you have ever seen in your entire life. Now, stuff that memory aside and imagine that the moon were made of money. Then stuff that imagination aside, because it's still not enough. If the mass of money were as large as Jupiter, it still wouldn't beas big as yo mommaenough. Maybe the mass of all of the stars in the universe, including black holes might be enough to measure the money you need to pay Yojimbo. Have I made this image accurate? Yes, I have.
I don't recall ever having Yojimbo as a "requirement" for victory.