Because of events like Tachibana's ?-3 and playing since day.......um, 5, sitting on 5m coins was a place I've been and gawd, it was agonizing. It took my crazy gacha pull to finally settle me down to 1m and it only stays that way because reissues gimme extra knights I can dump manyus into.
As for equipment, for those that don't know, should refer to the Equipment Upgrading Strategies Guide if you want to cut your cost down by half. As for me, now that I have almost 20, +10 Warrior Rings, I'm way too lazy to turn these in, so much work >.<