It is an important part of the program, but it does not resolve the entire case. The gift serves as evidence of the specified U.S. benefit; the applicant must also qualify for permanent residence, be admissible and have a visa available. Review the proposed classification and personal history before treating financial capacity as approval.
Connect the contribution with the remaining legal assessment
Bring the facts that might change the assessment: citizenship and birthplace, prior immigration decisions, current status and the intended individual or employer-sponsored route. Ask which eligibility questions require documents before the initial fee is paid. A significant contribution does not erase a prior refusal or automatically overcome inadmissibility.
Equally, it should not be described as irrelevant to eligibility: its evidentiary role is part of the official program, subject to the other requirements. Bring the personal history to the first conversation in written form, arranged by date, rather than answering questions from memory. A page listing entries to and departures from the United States, previous applications and their outcomes, and any period spent without status is more useful than a general assurance that nothing is wrong.
Where an earlier application was refused, obtain the notice itself if it still exists, because the reason recorded on it determines what has to be addressed. Financial capacity is one element among several, and treating the remaining elements as formalities is what produces an expensive surprise late in the process.