This entrepreneur is rightfully proud that he has managed to build a successful business, one that he has pretty much turned over to his family. Now, he's got time and financial security, and he wants to give a little back and make a few bucks in the process.
To earn money doing something that most people find more distressing than a root canal, you need to have something of recognizable value to offer an audience, even if it's only your notoriety. The fact is, most of the speakers you see at events around town are doing it for free.
It's not the speaking that provides gain for the speakers, but the opportunity to get in front of an audience and get exposure for his or her company, prospects for services or to sell a book. Speaking in public, for most of us, is a means to some other end.
In any case, my suggestion to the caller was to first try to gain some public credibility for his business to establish himself as an expert. From my perspective, the best way to do this is to share his story through publicity; that is, attempt article placement in the news media to build credibility. Then he might be able to leverage the credibility into speaking engagements.
This gentleman may very well have something of value to offer other business owners, but the world may never hear it because he has placed an obstacle in the way of his success. The trouble for him is that his business is a wholesale operation, and he's afraid that publicity will bring prospective retail customers, which he doesn't want to be bothered with.
Doing anything of substance often has unintended or uninvited consequences. Launching a new venture, by its very nature, is going to attract attention, wanted or otherwise, if it is to have any chance of succeeding.
If the potential payoff is rewarding enough, you'll find a way to get around the obstacles or, perhaps, find opportunities in them.