The core official payments are the gift to the U.S. government and the nonrefundable DHS processing fee, paid as the official process directs; State Department visa fees and medical-examination charges may also apply. Consultant charges are private, and a “placement fee” for a program with no placements is a warning sign.
Separate official payments from private charges, then question the private ones
The published framework identifies a nonrefundable DHS processing fee and, after successful vetting, the gift itself, with current amounts to be re-verified before any transfer. The official FAQ also warns that State Department visa fees and medical-examination charges may apply. Those official amounts must be paid only as the official process instructs, not through a consultant.
Professional fees are legitimate when they pay for real work: reviewing whether the underlying category fits, assembling the lawful-funds file, comparing the program with EB-5 and E-2, and preparing the application. A retainer for that is a normal private cost. A placement fee, a reservation fee, a private fee for expedited treatment or any payment routed into the consultant's account for onward transmission to the government should be refused.
Walt should ask for an engagement letter that lists each private fee, what it buys, and a statement that the consultant will never hold or transmit the gift. If the consultant will not sign that, the answer is already clear.