An EPIC Credit costs less because it is a building block used in the EPIC administration system. It is not a finished product. A single credit cannot create an assessment or report on its own. It takes multiple credits to generate one.
For example, a Workplace Profile requires 15 EPIC Credits. At the retail rate of per credit, the total cost is (15 × the per-credit price). Other assessments and profiles require different numbers of credits, so their total cost will vary.
Please note that these prices are retail rates. EPIC Account holders receive preferred corporate pricing, which can significantly reduce the cost per credit. This lower pricing is available because EPIC Account holders manage the (minimal) administrative tasks associated with creating assessments, whereas we handle those administrative responsibilities for retail purchases.