bonding with familiars is the way. granted, you need a few hundred of 'em, but seriously worth investing into. most of my notn chests came from doing the two-window method from sqld's moneymaking guide for half an hour a day, and i made a tidy profit. didn't grind nearly as much as i thought i would.

also, getting to opening 10-50 rusted/iron/gilded chests a day is wildly satisfying.