I've spent 50$ total on Nutaku Aigis, doing premium rolls, and Cellia was only unit I got out of it (fsckin' 6 copies of Kerry, I'm still salty). Raising units and accumulating resources was done exclusively from free stuff (lots and lots of manual dragon hunt grinding, ugh), so spending has nothing to do with AW-readiness.
And I'm quite new player, starting at the end of Karma event, so yes, pretty much everyone is at least at this level or better if they bothered to spend their charisma during big break.