in the post collapse times, US currency is meaningless. only rare metals will have value as they cannot be easily duplicated or mined. as such, they will form a basis for the currency.
surviving the first 6 months is the trick.
stay low... stay away from the population centers... and trust no one you’ve never met before
Things you can eat or use will be valuable
Food & water / firearms & ammo / necessary prescription medications & first aid / *a very hard heart*...because if you aren't capable of saying no, you will die.
Be wiling to die to your territory. Because if you aren't, they will kill you anyway.