Government filing amounts appear in the USCIS fee schedule, Form G-1055. Beyond them sit regional-centre administrative charges, immigration and securities counsel, source-of-funds preparation, translations, and later the petition to remove conditions.
Price the administrative layer before the capital
Hypothetical example: the couple budget the qualifying capital and nothing else, then meet an administrative charge from the regional centre, a separate legal bill for the source-of-funds work, and accountant time to reconstruct the bakery's history. Build the budget in layers: qualifying capital at the applicable amount, verified against the current official figure rather than an older article; the sponsor's administrative charge and whether any part is refundable; government amounts per the current G-1055 schedule for each filing including the removal of conditions; professional advice on both immigration and the investment itself; and translation and courier costs.
Ask in writing what is refundable at each stage and under what conditions, and ask what happens to the administrative charge if the petition is denied. Independent advice on the investment, separate from anyone selling it, is worth its cost.