If you still have a copy, it is worth just shy of $100 in used condition.

I have read the threads from a few years back about sharing a copy digitally. The rules are somewhat complex around this, given that the author is the publisher and is deceased. I guess further research is needed. What I do know is that anything published in the US before the 1920's is public domain, but this one was published in 1964. Hopefully the equivalent of "fair use" clause will apply here since the author can no longer profit from sales.