PF Flex charges more credits where we either provide more value or where we need to maintain marketplace dynamics. e.g.
More credits are required when a community has higher demand or increased competition, leading to more premium listings and decreased leads per listing and hence, an increase in credits for premium to ensure they continue to provide more value to customers higher leads per listing, or, or has an over-supply of premiums leading to lower leads per listing etc.
Fewer credits required when a community has lesser demand (e.g. low season) or has a lack of supply etc.