Evellum has a two-tiered pricing schedule whereby Individuals generally pay less than Institutions for an item. When the 'Product Details' link for each item is selected, the 'License Type' field appears under 'Pricing'. Institutional purchasers (Libraries, Universities, Museums, etc.) should select the 'Institutional' charge; the cost for Individuals is the default price.
If you require a site licence for a product so that it can be mounted on a central server and made available internally to all your staff and students, please see 'Site Licences'.