[cdawzrd]

RF Explorer is a "budget" option at around $300-400: http://rfexplorer.com/models/

Professional handheld spectrum analyzers are in the $3k-50k range from the likes of Keysight, Anritsu, etc.

[tegansnyder]

Many vendors will also rent out them by the day. There used to be a company in Denver that did back in my WISP days.