(Look at the bold for what I think is the easiest method)
There are a couple ways to get 55 coins in a run.
- Slowly building up money on a normal run by just never buying things. Stuff like Pageant Boy helps.
- Using a slot machine until it explodes and hoping it gives you a dollar. You will instantly have 99 cents.
- Running into a room that just has like 99 cents on the ground (happened to me recently). First time me or my friend have seen that in each of our hundreds of hours.
- Use the 2 of Diamonds card when you have 28+ cents. It will double your money.
- If you are close to 55 and have put money in your donation machine, you can go in the shop and use bombs on it to take coins out and get over the hump.
You can get the Quarter from pots and stuff which helps out by giving you 25 cents instantly.
The easiest way:Play Azazel on Greed mode.
(To unlock Azazel -
Solution for Azazel In The Binding of Isaac: Repentance)
Azazel is the easiest character to win with without upgrades. He does high damage and can fly off the bat.
Just simply keep all the money you get from each floor. You will get enough to hit 55 by the end of the 4th floor at least without needing to do much thinking