It's hard to go by a price in a book because there out of date so quickly after printed. Values in this hobby is like the stock market it goes up and down. The best way is to watch Ebay and other auction sites and look for sold signs pumps cans etc. and you can always ask here before buying.
The most recent auction of mostly globes pumps and signs was the first part of the Kyle Moore collection. Here's a link to the results.
http://morphyauctions.hibid.com/catalog/64039/october-5th-2015-premier-gas-and-oil-sale?tab=0
