If my count is correct I currently need 754 Mk III and 1035 omegas to finish off all toons non-zeta abilities (minus Probe Droid and Traya since they are the last two toons I need to unlock). Granted I don't need to max every toon, but it is a bit of a goal post.
I start saving omegas once I hit 10 zetas, then I save Mk III's once I hit 15. That generally works for me. I just put my 31st zeta on Chewie this morning so I am collecting again to up his other abilities and finish off Zombies new ability. Then I need to finish out BH abilities and contracts. Then I'll look at the subpar characters that need ability increase. I'll be happy if I can get to a point where I can horde Mk III's.