World Banknote Catalog

I figured. A revised ebay search yielded many more issues of the Satandard catalogs. How far back (edition/publication year) would you recommend as acceptable for general use now? Also, I see that I will likely need 2 volumes to cover most of the dates I intend to collect.

The pricing doesn't need to be up to the minute, so to speak, but recent enough I suppose to help me to avoid grossly overpaying for something. I am not going to have a huge collection, nor can I afford to go after the high end notes, so just enough of a reference to differentiate notes of some value from the common notes and recent enough to have a rough idea of current value.

I read somewhere that they like to renumber the catalog a bit. Is that still true in later volumes or true at all?

Thanks for the help.