The Best Book, With Prices, On Spanish Coins

The Calico (by Aureo & Calico) is the most accurate IMHO.
You'll get an estimate price though (nice to see scarce dates and compare values) - it's always a good idea to check auctions archives to see current market prices.
The book dates back to 2008 : http://blognumismatico.com/2012/04/...ca-espanola/

I don't see it anymore on their site (https://www.aureo.com/en), you should be able to find it used, or contact them to get it new (shipping will kill you, it's heavy .). I asked them a couple of weeks ago, they are slowly preparing an update but don't have any target (which means, not in the next two years at least .)

Ouch . each book has his own numbering system.
For the Calico, those numbers actually changed from the old version to this 2008 one :/

Here is a sample :

You are the first one from the US I see not using the KM numbers :)

Indeed, I was again checking out yesterday, for example for a Felipe II 2 reales from Potosi : essayer A,B and R were listed at the same price (while you can easilly find B, A is less easy and R is scarce).
The value there are comparative value, and sometime not that accurate (but still more than Krause :D )
There is also no value per grade (it's more a coin catalog than a valuation catalog - like Krause) - values written are for decent grade coins (AU50 ?) and much complete strike (for cobs particularly)