What's your purpose for using it? Home lab, small business production firewall or something else? The answer to that determines the license(s) you need.
The one you linked is FTD image. An ASA 5516-X can be run as a classic ASA with ASA software image (and optional Firepower service module) or as a Next Generation Firewall (NGFW) with Firepower Threat Defense (FTD) image.
Either mode can do basic firewall features with no additional licensing. To use the "next generation" features (IPS, URL Filtering and Malware Protection) you need to add licenses. They are available separately or in packages for 1, 3 and 5- year terms. There's also remote access VPN ("AnyConnect") in either basic ("Plus") or Advanced ("Apex") also with associated license terms.
Finally there's the support contract ("Smartnet") that also has an associated term and cost.
As you can imagine, the cost can vary widely according to which features you need and how long your want to buy the term license for.
