The US$15,000 processing fee is expressly non-refundable. Obtain a scoped quote for retrieving and reviewing the decision, then compare that cost with the value of resolving a fact that may change whether you apply. Do not assume a particular review price or that paying for review guarantees a favourable finding.
What the non-refundable fee does and does not buy
Only the US$15,000 processing fee is described as non-refundable; other government visa, medical and professional costs are additional and governed separately, so do not assume the whole outlay behaves the same way. The US$1,000,000 gift is requested only after successful vetting, when instructed — do not transfer the gift prematurely or assume a fee payment resolves the refusal issue. Budget any professional review separately.
Order the spending so the recoverable comes before the irrecoverable. A scoped review of the record costs a fraction of the processing fee and can be commissioned first; once the fee is paid it cannot be recovered, whatever that review later shows. Ask the reviewer for a timetable as well as a price, since a review arriving after the decision has been made has bought nothing.
Where several outlays are anticipated, write down which are payable once, which repeat at later stages, and which fall due only on instruction, so a single figure is not mistaken for the whole commitment.