Government filing charges from the USCIS fee schedule, a professionally prepared business plan and, for a direct investment, the running costs of a business that must reach ten employees. The capital itself is genuinely at risk.
The capital is the floor, not the ceiling
Hypothetical example: a Hampton investor budgets the qualifying amount and treats everything else as noise. In a direct investment the additional spending is substantial and unavoidable. A credible business plan with a defensible hiring model is a professional product.
Source-of-funds preparation covering a farm sale and a gift takes time. Government charges for each stage, including the later filing to remove conditions, are published in the fee schedule and change. Then there is the business itself: premises, equipment, working capital and a payroll that has to reach ten before the period ends, some of which may exceed the qualifying capital.
Above all, the capital must be genuinely at risk, which means a real possibility of losing it, and the family's plan should survive that outcome.