Beyond the qualifying capital, expect regional-center administrative fees where one is used, USCIS filing fees for the investor petition and later Form I-829, legal and accounting costs for the source-of-funds work, and translation costs. USCIS fees are published in the fee schedule, Form G-1055.
The documentation cost scales with how messy the history is
Grigor's capital figure is the visible number and the predictable one. The variable cost is the reconstruction of two decades of partnership history into evidence a stranger can follow, which involves accountants as much as lawyers, and which grows with every year that was handled on a handshake. Regional-center projects add their own subscription and administrative charges, disclosed in the offering documents, and those are separate from the qualifying investment.
Filing fees for the investor petition and for the later Form I-829 should be confirmed on Form G-1055 rather than estimated, since they change. Budget also for the possibility of a request for evidence on source of funds, which is common and which consumes professional time at exactly the point when the family wants certainty.