This spell should be 5th level. Not available in a potion or a wand. The reasoning is parties pitch in and buy a wand of this early on in a campaign and terrain is meaningless. Make terrain mean something again. I just assume see this spell removed completely.
Now I know everyone will say but compare the power of fly to other 5th level spells. Good argument, but sometimes I think mechanics should be sacrificed in the name of getting players to come up with solutions other than "5 more charges off the fly wand". Boring. Look at how much even high-level adventures emphasize terrain. Not only that, it just gives way too much advantage in an outdoor combat (or even a high celinged room) for a 3rd level spell.
