This spell and Spell Book Swap used to be tied for the highest magic level requirement of all spells, but the release of Miasmic Barrage took this title away from them. As of 23 August 2011, the spell Borrowed Power holds this title, because of its 99 Magic requirement.
If you're on Lunar Magicks, Ice Plateau Teleport is a great way to replace Ghorrock Teleport. It practically does the same thing, only the Lunar version of the teleport spell requires level 89 magic to cast. However, it costs around twice as much.