From Wikipedia -
…is a 1678 Christian allegory written by John Bunyan.It is regarded as one of the most significant works of religious English literature, has been translated into more than 200 languages, and has never been out of print.It has also been cited as the first novel written in English.
1678 .. it's waaaay out of copyright. If you pay anything for this, you're being ripped off.
Always free from Project Gutenberg: https://www.gutenberg.org/ebooks/131