After several hours of trying to break the game to fill up my Greed Machine, I figure I should mention the things that should be kept in mind if you want to try it yourself. I know this method isn't unique, but this post is meant to mention the details that may be overlooked so you, yes you, don't ruin a breaking run because you did something silly. Learn from my mistakes.

But before you start, I encourage you to at least beat Greed Mode with every Character. I imagine most of you have, but don't just go straight into it and overlook the fun new mode of Afterbirth. This method is meant to be used to prevent the 80-100 runs (numbers taken from this https://dl.dropboxusercontent.com/u/20380831/GreedMode.html) it takes to donate 1000 coins the the machine.

The easiest way to create a broken run in Greed Mode is acquiring the Blank Card with the 2 of Diamonds, buying and using infinite batteries, and looking for the Glowing Hourglass with either a ridiculous build or the Chaos Card. Resetting for the Blank Card (which isn't always necessary, you can get the combo pretty consistently) and buying every card you can in the shop is your main goal. Azazel is probably your best character for this run, since he is not nearly item dependent as other characters. This allows you to cycle through cards with all of your money.

Anyway, once you get the combo and have a battery for sale, exit and continue the game to "save". If anything goes wrong, say, consuming your 2 of Diamonds, you can close the game from the Task Manager to revert to your "save" state. You can then go crazy, and buy nearly any item you can.

Items to look for:

The Battery (item), Habit, 9 Volt - None are necessary, but they may add a fail-safe in using the Glowing Hourglass on the Ultra Greed floor.

Starter Deck - This can allow you to hold the Perthro Rune along with turning all pills into cards if you haven't found the 2 of Diamonds yet.

Deck of Cards - Use the infinite batteries to look for the Chaos Card. Its pretty rare for to find, so be patient. Mom's Bottle of Pills can be used if you also have the Starter Deck. (also if you are popping every card, make sure you use The Tower in a different room, or you may reroll your battery)

D6 - Rerolls any Space Bar items you bought. Be careful though, since that will include your Blank Card. Look for Wheel of Fortune cards to create the Crystal Ball in a different room.

Glowing Hourglass - Only adding this because I, uh, did accidentally reroll this and had to redo about five minutes of item grabbing.

Items to avoid:

Car Battery - I'm not totally positive, but I think using the D6 or Blank Card with Perthro double rolls items, and could remove the Glowing Hourglass from the pool.

Chaos - This item will only slow you down. If you aren't aware, Chaos pulls a random item pool for each item encounter, so if you deplete a pool, it will make Breakfast appear. Without Chaos, you can't pull from empty pools.

Credit Card - Using this item in the shop ruins the restock passive in Greed Mode, so it could mean you can't hunt for the 2 of Diamonds or rebuy batteries.

Dice Shard - Using this will reroll your battery pick up from the pool, meaning no more infinite money. And I hear money is pretty good in this mode.

Missing No. - Just don't.

Little Baggy - Turns all Cards into Pills, so bye bye 2 of Diamonds.

So after you have your fun and get the Glowing Hourglass and the Chaos Card if you wish, roflstomp your way to Ultra Greed, kill him and donate to the Greed Machine. I think the amount you can donate is seeded at 20% jamming rate, so have your fingers crossed that it won't jam after one coin. Then use the Glowing Hourglass, and have so many deja vu moments of Greed's Scream than you care to have. Don't forget to exit and continue to "save" every time you get a key item.

Good Luck, I hope this helped.

If you think i missed anything, please tell me and I'll edit it in.