Great question that pops up on the coin and paper side often.
Even greater responses! Thanks to you all.
I've been looking at the notes that pop out at me as works of art and always intend on buying the best I can, usually Uncs and with the PPQ and EPQ
PMG and PCGS Currency
It's hard not to pull the trigger too quick and learn, learn, learn. If I miss something, oh well, something else will come along.