And the average for the years I have available for swap is as follow according to the K&M books:
F: 14$ VF: 16$ XF: 22$ UNC: 90$
Now, this instantly arouse my suspicions because the coin is a 27.07 gram, Silver .903, Pre-1900, Crown-sized.
This means it contains (27.07gr x 0.903) = 24.44 grams of PURE SILVER.
At yesterday silver value (0.68 dollars) this means each coin has 16.62 dollars worth of silver alone. So according to the books, my coins bellow XF are worth less than their melted value
And even worse, some of the books are the 2013 editions, which means they were published back in 2012 when the silver price was at 1.15$ per gram, so this means by the time the books where edited and published, the silver content on each of the coins was worth 28 dollars alone!
So I had to search other ways of valuating those coins, and found other books that price Mexican coins alone, and found an interesting note concerning the "misleading pricings on the K&M books for the Federal 8 Reales". It reads as follows:
"... clearly an editorial mistake, as it clearly looks like they forgot to place an annotation specifying that the values given are to be added to the BV of the coin, so it should be BV+##$ prices..."
All this can be confirmed at the NGC coin database, being them one of the main contributors to the K&M catalogs makes the error even clearer.