Commander Masters is the first Masters set created specifically for Commander, featuring iconic reprints alongside cards that were previously exclusive to Commander preconstructed decks
While I firmly believe the idea that taste is subjective, and quality is not, I find it disruptive to the larger discussion of Magic art to try and codify which artwork is the better, or if A is better than B, etc
WotC usually does that to show different versions of a mechanic at different power levels
Allowing you to play a different threat on your turn when they are tapped out
A sealed pack out of a closed set works like a lottery ticket on a fixed prize pool, and its price tracks what can come out of it
Card condition is generally graded on a scale of damaged/unplayable to near mint/perfect, with card prices affected by card condition