Correct me if I am wrong, but Price doesn’t discuss at length a model for the Christ Myth theory in that work, he more or less discusses the comparative religion with an emphasis on Buddhist theological parallels. His more recent work, The Christ Theory and Its Problems is the one you’re looking for.
No, he doesn't discuss the "model" but he does attack the authenticity of the gospels and the parables in the book which is a carryover of his contention that the Jesus character is in fact a composite of earlier god stories. He clearly defines this in the articles he published on the topic as well. I'll put The Christ Theory on my reading list.
Cap't Jack