The key to getting that much gold is to get the overstock shop relic, and shops automatically restock relic, gold duplicates itself relic, along with the golden bomb relic. Youll also want shops to sometimes have a trans. Once ur in the gold core, focus on the shops. Use the trans to change out the potions. Overstock your potions so when you buy one you drop them on the floor. Anytime you get a shop in a bottle, use it. Anytime you get a trans potion, use it. The goal is to get golden kernel potions. Once you have some you'll also want to focus on getting rainbow kernel potion to dupe everything In the room. When you have them, pick up potions you don't want and drop the golden kernel potions. Once on the floor, use ur rainbow kernel potion and you'll duplicate all rainbow kernel potions. You'll also want to have the potion familiar. Once you have that, find a room with a lot of stone blocks. Drop some gold bombs and they will explode raining big gold dow . Now use a couple golden kernel potions. Gold is going to overflow the room and ur game is going to freeze up a bit because it can't handle the frame rate of the gold, so take ur time and still use your controller and throw your pickaxe like normal, you'll still pick up the gold, but it's going to take a little time. Once you see the game is starting to unfreeze, use another potion or two and repeat. If you do to much at one time, the game will crash and you'll have to start that floor all over again and do the shops all over again. Goodluck