PCGS Price Guide indicates that there is only about a $20 difference between MS63 and MS69 PCGS graded
ASE's. The real jump seems to be when you hit MS70 and really only several
ASE's older than 2009 seem to be worth big bucks in MS70.
To me,
ASE's are just bullion. That is why I specifically try to buy them in ugly low grades to keep the premium low.