As two different kinds of money. The Gold Card gift is spent and never returns; EB-5 capital is invested at risk and may be returned if the project succeeds. Compare after-tax cost, liquidity and what the household holds at the end, not the headline numbers.
One is an expense, the other is an at-risk asset
The contractor's accountant will frame this better than any immigration brochure. Under the Gold Card as published, the household's outlay is the gift and processing fee for each person included, and none of it comes back; it is a gift to the U.S. government, not a purchase and not an investment.
Under EB-5, the household places US$800,000 or US$1,050,000 in a new commercial enterprise, pays the regional center's administrative fee and the USCIS petition and integrity-fund fees from the fee schedule, and holds an interest that may repay capital, may pay a modest return, or may be lost. The two should be compared on what the family's balance sheet looks like in ten years under each scenario, on the tax treatment of a gift versus an investment loss or gain, and on liquidity, since a financed gift converts a one-time outlay into years of debt service. Add the legal and translation costs of documenting the fleet sale, which are similar for both, and the per-person immigrant-visa charges.
The cheaper route on paper may not be the cheaper route after tax.