The official framework describes the US$15,000 processing fee as non-refundable, and the US$1 million individual gift is a gift to the U.S. government rather than an investment; neither is described as recoverable. The sponsor's own terms may add repayment obligations. All figures should be re-verified on the official page before payment.
Assume nothing comes back, then plan
The safest working assumption is that money paid into the program does not return. That shapes the sequence: eligibility analysis and admissibility review before the processing fee, and the gift only when the process instructs it after vetting. Distinguish the three streams of cost.
The processing fee is stated to be non-refundable and is paid per person. The gift is stated to be a gift to the U.S. government, which by its nature is not an investment and carries no return or equity.
Ordinary immigrant-processing costs such as medical examinations, consular or adjustment fees under the USCIS fee schedule, and document preparation apply in addition. If a sponsor pays, add a fourth stream: whatever the sponsor's agreement makes repayable by the employee on departure. An applicant who cannot afford to lose the processing fee should not pay it on the strength of a customer's enthusiasm; an applicant who can should still confirm the official terms on the day, since the program's published terms may change.