Macao 5 Avos 1952

Hi, I would like your opinions and comments on this coins grade and I have a question .. I use the Krause SCWC from 2009 and notice that for most the prices listed start with UNC but that for a others it gives prices for a coin in the BU category. If these categories correspond to the difference between a MS60 and say a MS69 graded coin, then why isn't there a pricing difference shown for all coins? Just this books standard that a coin shows no visible sign of wear or handling even under a 30 power microscope to be considered Uncirculated an extremely high hurdle to pass; now personal interpretation comes into play with mint luster and bag marks to pass as BU? What a game this is!