It allows the player to tap creatures to put a number of charge counters equal to those creatures' power onto the permanent with station
The worth of a card is not necessarily in its monetary value, as each and every card can help one in any given situation, depending on what needs to be done
That being largely a matter of "these seem interesting, but likely won't see play unless the right deck comes around." There're a few exceptions, which I'll touch on, but to save you, the reader, your sanity by not reading the same line over and over across 20-30 cards, I'm going to talk about them mainly in groups here and now
It is another excellent sacrifice outlet, albeit a one-time use, most of the time
You have the power-and-toughness changers (Gift of Granite, Primal Cocoon, Defensive Stance, Sensory Deprivation)