You should just get to about lvl 20 by the Ogir-Yensa Sandsea. You REALLY don't need to and shouldn't go all the way to lvl 30.

I wonder if you would dare taking on the level 45 beaty that hovers around =P
The Salamand Entite will still be too much even at level 30, since it can still do about 1500-2000+ to everyone at a time with Firaga. And at lvl 30 you probably only have about 1500HP anyways, unless you get Augments. Unless you get lvl 3 Quickenings for everybody, the Salamand Entite will easily kill you at lvl 30.

But hey, at least you probably won't have trouble with Demon Wall #1. Especially the easier Demon Wall #2.