Omega Ruins. ....you set yourself up for it.

Firstly, calm down!
Secondly, you can bribe 30-40 Lv. 3 key spheres from Demonolith for 900,000 gil. If you go to the monster arena, you don't even have to wait to encounter them.

Also, you can bribe chimera brains for 2 lv. 4 key spheres (which I was just informed of the other day...) for 196,000 gil.