Separate the government filing charges, published on the USCIS fee schedule, from legal fees, from the cost of forming the U.S. entity, and from the facility's own start-up budget. The last item is a business expense that also serves as evidence of capacity.
Where the budget lines blur
The immigration budget is small next to the facility budget, and the danger is confusing them. Entity formation, registered-agent fees, the lease deposit and equipment purchases are business costs; they do not belong in the immigration fee line, but the records of paying them are the evidence that the company can support the role. Ask counsel to quote the eligibility assessment, petition preparation, premium processing if wanted, the extension petition in year one, and any response to a request for evidence as separate items, because a new-office case is more likely than an established-office case to draw questions.
Include the L-2 applications for the family. Confirm government amounts on the fee schedule at filing rather than at planning, since they change. Keep a ledger from day one that records what the facility spent and hired month by month; that ledger will do double duty as financial control and as extension evidence.