- If arcane mark doesn't work but cantrips do, close range has its uses. Though keep in mind that by level 7 you probably won't be using it as much (decent number of spells + a large arcane pool + pearls of power = better options to cast each round than cantrips)
YMMV
In this circumstance, could you not use a Cracked Orange Prism to add Touch of Fatigue to your spells prepared.