Hi Michael.

Welcome to the Club! There are no dumb questions, and a lot of people on this Board that are willing to help.

R-1 Extremely common 2000+ known survivors
R-2 Common 751 to 2000 known survivors
R-3 Fairly Common 351 to 750 known survivors
R-4 Scarce 151 to 350 known survivors
R-5 Very scarce 76 to 150 known survivors
R-6 Rare 31 to 75 known survivors
R-7 Very rare 16 to 30 known survivors
R-8 Extremely rare 8 to 15 known survivors
R-9 Exceedingly rare 4 to 7 known survivors
R-10 Impossible 2 to 3 known survivors

Info from the 4th Edition "The Official U.S. Casino Chip Price Guide" by James Campiglia & Steve Wells.