i.e. a person who earns a living (or a portion of it) from public speaking.
A single word would be preferred but up to 2 words max since I am working with a word limit myself.
Spokesman noun A person who makes statements on behalf of a group or individual: ‘a spokesman for Greenpeace’ - ODO
I'd hazard a guess, though, that people who pay to listen to a speaker do so for the content delivered, rather than the speaking itself. It may be more useful to seek a term relevant to your subject matter.
People who advertise this service on their websites tend to call themselves the following:
Here is one example of many: https://www.jessicacox.com/about-jessica/
An orator? That's about the closest word I could think of.
How about a Goldman-Sachs chinwag? One can never be sure that any bon mot uttered behind closed doors on Wall Street will never emerge into the cold light of day and thence into the media's spotlight, but at $250,000 a bung, this has got to be a nice little earner for some. (Wikileaks).
Goldman-Sachs: A US financial services conglomerate (Wikipedia);
Chinwag: slang -- Conversation, chat. (Merriam-Webster)