Is there an official answer to the way spells care about a monetary value?

Battle Master Feinting Attack maneuver discriminates against polearm users

Would a Way of the Open Hand monk be limited to picking a single monk weapon?

Can you cast feather fall in time with 1 reaction, considering the “Xanathar’s guide” rules on falling?

I would assume that casting a spell would require a minimum Intelligence

If the caster polymorphs themselves into an intelligence 1 or 2 creature, why it doesn’t interrupt concentration on spells?

When one has invisibility cast upon them unknowingly, do they know they’re invisible?