Staroptions are not a currency which can be independently traded, so they have no specific value. Staroptions come from some underlying ownership (a deeded week, a Flex product, etc.) and don't exist until you get to 8 months before desired check-in date, that's when the underlying ownership automatically converts to StarOptions.
People often talk about SOs as if they were a product one can buy or sell directly, that is not the case.