The broker may be good, but he also had the full details of the company and person he was dealing with. A 60+ yr old company must be doing something right and have access to the resources to purchase a 6 figure name. Like you said, if the potential buyer doesn't have the cash then no amount of talk or convincing will work. The other advantage of a broker is that they are a third party, so whereas the domain owner might be viewed as a huckster saying anything to sell their domain, the views of a third party person who the buyer assumes has a lot of experience with domain valuation might carry more weight.
How long did it take the broker from start to getting the sale?