It's an interesting debate, certainly.

In my case, I'm at Levi, short an WSB for it (have: Kain, Shantotto, gen-2 chains of both flavors). Either one of Ashe or Lightning's WSB would certainly get past, then I'm in good shape for Ifrit after picking Tidus on the package select.

Now, the only other sources of lightning damage that I can see in the near future is the T0 B2 (Queen, but no glint) or FF1 (Master only - Matoya is unusable because Shantotto takes the skills).

The banner itself is definitely meh. I have Bartz WSB and Tyro USB4 already.

I think I should pull.

As an aside: The fact that you're even talking about 100 mythril being a "big investment" is ... scary? worrying? disgusting? Dunno what word to use there. You're not wrong, of course - as I've said multiple times, the requirement for what people need to get to clear content has changed drastically, but the mythril income hasn't increased to match. (And in fact, it seems to be going down.)