A PSA 10 card can sometimes sell for many times the value of a PSA 9 card, making them highly desirable
Unfortunately, there arent many turn 2 creatures that make it Day for this to matter, and beyond turn three, this measures up terribly against whatever your opponent is doing (and already is poor against most two drops)
(8/7/2020) If you cast a spell "without paying its mana cost," you can't choose to cast it for any alternative costs
There's no single 'best' booster because it depends entirely on whether you're drafting, collecting premium variants, or chasing specific Commander staples
Cori-Steel Cutter was previously discussed and was simply an absurd threat and value engine
Even several years after its release in August 2017, this expansion retains a constant appeal on the collecting market