When a person is so broke that they resort to spending their 2 dollar bills. Most people avoid spending 2 dollar bills because of the rarity of these bills or because of a superstitious notion.
My uncle filed for bankruptcy right after he started dipping into the 2 dollar fund.
That guy must be broke, hes dipping into the 2 dollar fund to pay for that bag of chips.
Jim: Hey man, can you let me borrow some cash? I don't want to dip into the 2 dollar fund.
Stan: Sure, I hear ya. Neither would I!