If you don't care about earning the certificate, that's fine. Once you purchase this course, it is yours for life.
After you graduate or your days expire (whichever comes first), the only areas locked will be the quizzes, instructor-graded assignments and the Question & Support function. Other than that, you will still have all the lessons, recipes, live events, etc. to review at your leisure.
If you ever decide to complete your certificate at some point, you can purchase an extension to unlock the assignments so you can complete them and graduate from the course.