This table shows the total annual cost for 3 Season Passes at Six Flags with the Premium Dining plan against 3 memberships with Premium Dining during the Halloween sale (September / October 2020).
This page compares the Six Flags Halloween Sale 2020 costs for passes vs. memberships for 3 people. For a different number of people (1, 2, 4, etc.) see this page.
Season pass is a much better value, saving anywhere from $65 to $380 over the year, depending upon the Membership level chosen.
Costs below do not include taxes. See this page on the Six Flags Over Georgia for current prices for tickets, passes, memberships, dining plans, parking passes, flash passes, etc..