a couple things I can tell you. I have the exact same items/gear as the person in 1st place (others in the top 100 have it as well).

all of these items can be dropped by fighting bosses or from the daily free pachinko roll (and now the daily missions as well). as I have never done the x10 rolls in any pachinko either free or kobans.
(I got all my gear from dark lord, mostly)

even though I am placed around 1k, I can easily defeat the majority of players with more "rank" than me. I deal 1442+ on normal attacks without buffs or crits.

but I can tell you, it's not worth it for me either. as fighting from the tower menu only gives mojo, while fighting from the battle grounds gives exp and a little bit of cash as well.

I think getting a higher lvl so that you can buy more stats is more important than rank. I max my hardcore stat whenever I lvl, though my girls' levels are bottlenecked by the short supply of exp items (12 hour restock), and I'm not gonna blow my cash on pachinko either.

things to think about.