mtg cards like ghostly prison (#19) (foil) (borderless) —Great Threshold of Monserkat inscription Mtg Precon Ghostly Prison Commander

It's probably a bunch of RTR bulk and the seller is trying to "get their money back." (there seems to be a common misconception among people selling their cards on Craigslist that their cards should be worth at least as much as the boosters they opened to get the cards)

The calculator spits out a few numbers if you want to know the chances of drawing fewer than, equal to, or greater than one white source

I would even consider running Steelshapers Gift to find my Greaves

According to TCGPlayer, only seven Gem Mint and 10/10 cards are known today

Eminence is a truly busted ability, even when it's as fair as this one