Good guide, there are many coins that are low cost in the catalogues purely because there are no sales records Try finding one of these - a circulation issue 1883 2 centavos from Bolivia mintage 250,000 Krause VG $3.50, F $7.50, VF $15, XF $50, Unc $85 You can always find a proof though:- http://www.ebay.co.uk/itm/1883-BOLIVIA-2-CENTAVOS-ESSAI-UNC-PLAIN-EDGE-/281283702313?pt=US_World_Coins&hash=item417dd0ae29 The same holds true for many copper minors even of supposedly common 20th century issues, mintage is no guide to availability David