Paying is not the test. The official framework routes Gold Card cases through EB-1 or EB-2, and each has its own eligibility rules. Whether a tradesperson with a successful business fits one of them is the question to settle before paying the processing fee.
The gift opens a door to a category with its own lock
The official page and FAQ describe a sequence of fee, vetting, gift and then an immigrant petition in EB-1 or EB-2. Those categories were not created for the Gold Card and their requirements are unchanged by it. EB-1 asks for extraordinary ability, an outstanding academic record or a multinational executive role.
EB-2 asks for an advanced degree or its equivalent, or exceptional ability shown by meeting several listed criteria such as a licence to practise, ten years of experience, recognition for achievements and membership in professional associations. A journeyman plumber who has grown a company for twenty years could conceivably document exceptional ability in business, but it is a real evidentiary exercise with no guaranteed outcome. The consultation should test that first.
If the classification cannot be established, the gift buys nothing, and the framework as published does not describe a refund of the gift once made. Re-verify the current terms before relying on any of this.