This is a major portion of my scrap iron. There are some pictures of my #1 iron pile of mostly rotors in one of my old threads. For my situation, they store old rotors, etc under a bench or outside against a wall (this is really rural - nobody bothers it). I go around monthly and buy whatever they've got. Not sure of what you're saying is the price in Hawaii - but if it's thirty cents a pound, that pretty good. Rotors are #1 iron and I get thirteen cents a pound. I stockpile till I've got 2-3 tons, then haul them up to the yard. Rotor weight varies, but I figure an average if 13 pounds. At .30 a pound, that's almost $4 a rotor!!!
Don't bother with pallets, boxes or tubs. They won't hold them and you couldn't lift them.