Self-study is included as part of a course enrollment. If you're interested in self study before a course, the most cost-effective option would be to purchase the course but choose a date that begins a couple weeks, a month, etc. from the date of enrollment. Then you'll have access to the self-study resources for those couple weeks, month, etc. and can begin your course on the scheduled date, after the self-study.
Here's a link to an explanation of our pricing structure:
https://grockit.com/gmat/products
If you decide to enroll, you can use the coupon code andrea for $50 off your course.