Background: We're a 22nd-23rd level party: rogue, warlock/low wizard, druid, paladin[freedom] of Kord, and me, a cleric/sorcerer Mystic Theurge (of Orboros, which in this universe is one of the two deities of the elves).
Our party in general, and my character in specific, is very big on battlefield control tactics. (I also like economy-of-actions games, and sometimes end up doing 5+ "actions" in a round. It's fun.) Baleful Transposition, Bigby's Grasping Hand (aka Enveloping Wings of Orboros), bull rushing mooks into Prismatic Spheres...you get the idea.
The sorcerer/wizard spell list in this world is pretty limited (it's loosely based around the Dying Earth sequence by Jack Vance), and so we need DM permission for spells outside the approved list. I recently asked for Regroup, which lets you teleport all of your allies into squares adjacent to you (or nearest equivalent).
It's a 3rd level spell. The DM is hesitant to allow it at this level, because it's awfully good at a lot of things (stuck in lava? grappled by a balor? All solved with Regroup!), and wants to put it at a higher spell level, to balance it out. This has precedent in the magic system: for example, "3.0 Haste" (called Spell of the Slow Hour) is a 5th level spell. (It gives you one standard action that happens at the end of every round, and lasts for 1/2 caster level rounds. I always Extend it when I cast it.)
Any thoughts on what might be an appropriate level for Regroup?