If I already own the Greek Grammar Ontology then why should I need and or buy the book The Morphology of Biblical Greek by William Mounce? It looks like a good resource but it is very expensive. Are there any logical comparison to books that are like Mounce's work?
Did you actually look at the first book? It is simply and index to a number of grammar related resources. It provides links to works that have information similar to Mounce. You need to look at what you have, the level of detail it is at and determine for yourself how useful additional information would be to you.
I did and it looks good. The Greek Grammar Ontology is essential to me. I do not understand why the book by Mounce is always suggested. I understand Mounce's Morphology of Biblical Greek is a companion to his grammar book. In his basic grammar, Mounce believes that it is easier to memorize the underlying rules than to memorize the patterns of individual words. Is that still his case in point in the morphology text? Can I use another resource in Logos to do what Mounce does in his morphology textbook?
Mounce believes that it is easier to memorize the underlying rules than to memorize the patterns of individual words. Is that still his case in point in the morphology text?
Yes
Can I use another resource in Logos to do what Mounce does in his morphology textbook?
Not in Logos - learn to read Proto-IndoEuropean and the phonetics rules of change leading to the Koine Greek language.
Is that still his case in point in the morphology text?
Certainly not the only point.
What I am trying to determine is this main referential point. What in Mounce's Morphology is different than what I have in Logos? Can I find what is accessible in Mounce in Logos with their tools?
You are asking the wrong questions and, therefore, not noticing that you already have the answer. Most grammars are designed assuming that the student will mindlessly copy paradigms and memorizing them without understanding anything about them beyond "well, that's what my teacher said." Mounce's Morphology assumes that the student will learn the phonetic/morphologic rules behind the paradigms so that they can apply them to any new word that comes along. The student therefore understands the differences between different paradigms and explain what traits in the word causes the results. Logos treats Mounce's Morphology as a Grammar.