Efficiency can be determined simply by the reward you receive at certain mana costs (Counterspell and Cancel do the same thing, but Counterspell costs less), the total payoff you receive from a single card (Hull Breach and Decimate are both good cards, but Decimate usually covers much more ground), or the payoff you receive in conjunction with other cards (Anointed Procession makes other token production cards completely absurd if unchecked, which is usually better than adding one more card that simply makes tokens like Spectral Procession in a token strategy)
In our example Play Booster, two of the best threats are Relentless X-ATM092 and Gix, Yawgmoth Praetor as "The Shadow Lord." Relentless X-ATM092 is a high-power creature that forces your opponent to block or take damage, while "The Shadow Lord" draws cards over the course of the game
If multiple removal-heavy decks like Jund, Mardu Pyromancer, and Jeskai Control find homes in this brave new Modern world, I could see this cards stock going up considerably
The art features a cute raccoon, which likely also contributes to the price tag
While Ruby singers have remained a fringe strategy in competitive events, Powerline has appeared in Set Championships, and that drove a little extra demand for the Enchanted version of the movies most memorable song
