I suppose it depends on what you are looking for exactly. Are you looking for a basic intro that is easy to understand, or something that gets a bit more detailed and might take more effort to work through?
Germain Grisez’s classic three volume set is still used by many. The full text is actually available on this website:
I’m not familiar with the title you mentioned. It looks to be a self-published edition of a work that is in the public domain. It looks like you can get the Kindle version for free:
You can use the free Kindle desktop app to read it even if you don’t have a Kindle. I would go that route. You can check it out and see what it is like. I also googled the title and a number of websites have the text of the book online for free (like here). No sense paying for what is basically some guy formatting a public domain text and putting it into a print book.