I am working on a new offcie building project and I have already the LEED Reference Guide for Building Design and Construction (Updated on January 2016)
but I noticed that theere is a new version updated on  (August 2019) 
the new version costs 219 US Dollar for PDF copy! as you can see in the link bellow.

https://www.usgbc.org/resources/leed-reference-guide-building-design-and...

 Should I buy the new updated version or the version is have already is still valid?