Start from the offering's own figures. List qualifying capital on one line, the administrative fee on another, then government filing fees, legal fees and translation separately. Written professional quotes are obtainable for legal work, so a documented budget is realistic rather than speculative. Payment timing varies by offering.
One line per obligation in a hypothetical spreadsheet
Take a hypothetical manufacturing project in Arizona: US$800,000 in capital, a US$60,000 administrative fee, plus filing and professional fees. Keep a column recording the source and the path of every transfer, since both are examined. Nothing requires that all amounts be paid in one instalment, and arrangements showing you are actively in the process of investing may qualify, depending on the documents.
Ask the regional center for a written statement of every fee and where it is paid from. Independent legal review of an offering document is not the same service as preparing a petition and should be priced as its own engagement. The immigrant-visa application or adjustment of status carries its own government fees. All government amounts are on USCIS Form G-1055 and are revised periodically.