The Form I-526E or I-526 filing fee on the USCIS G-1055 schedule, the regional center’s administrative fee if one is used, later immigrant visa or adjustment fees for each family member, and the Form I-829 fee at the end. Professional, translation and source-of-funds accounting costs are additional.
Budget the fees around the capital, and keep them separate from it
The investment itself must be the full qualifying amount at risk in the enterprise; fees paid to the regional center or to lawyers do not count toward it, so the family needs the threshold plus the costs. Read the petition fee from Form G-1055 on the day of filing rather than from a project brochure. Regional-center administrative fees are set by the project and may be nonrefundable; read the offering and escrow documents for the actual term.
When the petition is approved, each family member processes an immigrant visa at the consulate with State Department fees and a medical examination, or files for adjustment of status inside the United States with the USCIS fee. Two years later Form I-829 carries its own fee, and biometrics may be charged. Wire and conversion charges must be documented, because the amount reaching escrow must still meet the threshold.
Ask the project whether its escrow returns the capital if the petition is denied, and get that term in writing.