Pennys Alternative Art card is currently selling for anywhere between $23 and $25
MTG tutors make it much more likely you'll have the answers you need, right when you need them and can therefore really boost the power of a Commander deck
This has less of an impact on a Limited format as a whole, but giving players the chance to play with Swords to Plowshares or Brainstorm in a non-cube 40-card format is something that will excite players about their Limited deck
As for The One RingThe One Ring, holding up seven mana to cast it at instant speed is a lot, but in general with an Alchemist's RefugeAlchemist's Refuge in play, you can just pass turn and hold up all of your lands fairly fearlessly
A Multitude of Common, Uncommon, and Rare Cards : Complete your albums, find essential Trainer cards, and round out your collection with cards from this set
While you cant Saw in Half your commander or a legendary creature for ultimate value, the possibilities this card can lead to definitely add up
