The processing fee is non-refundable and starts vetting; it does not hold a place at a fixed price, and the terms can change. Pay only when the underlying eligibility case is assembled and the family decision is made, and re-verify the official terms on the day of payment.
The fee starts a process; it does not freeze the terms
Hypothetical example: the dentist is two years from being able to leave her practice but worries the amounts will rise. Paying the US$15,000 fee now would begin vetting and commit her to the process on the terms then in force, without any published assurance that a later gift amount would be locked. If the application proceeds to a decision before she is ready to move, she would face a residence obligation she cannot yet meet, and permanent residence not taken up or maintained can be lost. The better sequence is to spend the two years preparing: assemble the EB-2 evidence, decide on family inclusion while the children are under 21, take tax advice on the payment, and plan the sale or transfer of the practice. Then, close to readiness, re-read the official page and FAQ, confirm the current gift, fee and process, and pay the fee when she can follow through.
Hypothetical example: a theatrical-lighting designer plans to sell her studio next spring and asks whether a payment now will reserve the program for later use. Her first review should separate readiness to immigrate from fear of a changed price: confirm the current official terms, assemble the EB-1 or EB-2 evidence, decide family inclusion and verify that the intended move can follow a favourable outcome. The applicant's payment goes to the U.S. government; it is a gift and processing charge, not an investment in the studio or a conventional visa purchase. A receipt cannot replace the underlying immigrant eligibility, and a non-refundable payment made before the plan is executable merely creates a cost without solving the relocation decision.