you see it as an abuse because you are in a single player, comfortably swimming in a sea of gems, and having already won against AI without you wanting to give the death blow
Am I right?
Because in MP its a big trade off. 100 gems for a magical skill, wow!
Anyway in MP I prefer to let uber alchemy kick in with the wish. 100 astrals give you 175 gems, or if you prefer 75 astrals leading to 6 packs of 25 gems. Thats exactly the reverse of standard alchemy where you have to spend 2 astrals for one gem. cool, quick and efficient (but not an abuse too).