The use of the word “more” in “more money more problems” indicates that both money and problems are continuous variables. Thus, the statement should be modeled with predicate logic, but with analysis. As phrased, the sentence implies a positive derivative between the two variables. If assumed to be valid over the complete range of possible values, “less money, less problems” indeed follows.
If assumed to be valid over the complete range of possible values,
Which is where this logic fails. The saying is usually constricted to the range of “a lot of money” to “way too fucking much money”, with money less than “a lot of money” not included. Therefore the derivative can be positive, negative, zero, or anything really. Also to be pedantic technically the derivative doesn’t need to exist for a positive Δmoney to yield a positive Δproblems.