No. The Gold Card is an official program built around a gift to the U.S. government plus a processing fee, attached to an immigrant framework described on the official site; EB-5 is an at-risk investment in a job-creating business. Neither is a purchase of a visa, and the two are not interchangeable.
Two programs, two legal ideas, one common misdescription
EB-5 grants conditional permanent residence to a person who invests qualifying capital in a new commercial enterprise that creates at least ten full-time jobs, with the money at risk and the investor engaged in the business. The Gold Card, as established by Executive Order 14351 and described on the official program page, involves an unrestricted gift to the U.S. government and a processing fee, with applicant vetting, and it is not an ordinary nonimmigrant or immigrant visa category of the familiar kind.
A retiree who has sold his business is not investing anything under the Gold Card; he is giving. That changes the questions he should ask: not what the return is, but what the official terms promise, which family members are covered, what the underlying immigrant category is and whether it fits his situation, and what happens if the framework changes after payment. Because the program is recent, all of those answers should be taken from the official page on the day of the decision rather than from a relative or an intermediary.