Significance of a problem shouldn't be considered from the same point of view as pricing an asset, by face value.
Open problems concerning prime numbers can be considered as large floodgates, waiting to be opened. Their applicability is likely to be infinite. Pick up any subject, try to quantify some behavior, sooner or later, primes will make an appearance. In fact, you should really do this; read the first few chapters of an elementary number theory book, then try to represent your area of expertise in a way that involves primes.
Perhaps in a few decades, or centuries, by tracing a certain technological improvement back in time, we'll be able to place a $-value this work. You can already do this now, for other (probably all, if you can be bothered) areas of (previously abstruse) mathematics, for example Group Theory -> Spectroscopy -> Biomedical Spectroscopy, or Algebraic Topology -> Improvements in semiconductors.
Open problems concerning prime numbers can be considered as large floodgates, waiting to be opened. Their applicability is likely to be infinite. Pick up any subject, try to quantify some behavior, sooner or later, primes will make an appearance. In fact, you should really do this; read the first few chapters of an elementary number theory book, then try to represent your area of expertise in a way that involves primes.
Perhaps in a few decades, or centuries, by tracing a certain technological improvement back in time, we'll be able to place a $-value this work. You can already do this now, for other (probably all, if you can be bothered) areas of (previously abstruse) mathematics, for example Group Theory -> Spectroscopy -> Biomedical Spectroscopy, or Algebraic Topology -> Improvements in semiconductors.