Buying the parcel and completing the manufactured-home project are connected decisions, but they do not create one universal closing-cost total. The contract, financing structure, title work, records, inspections, and project scope change the categories and timing.
Short answer: Build the land-closing budget from written categories instead of a percentage: contract deposits or due-diligence payments, lender and settlement charges when financed, title and legal work, recording or government charges, taxes and prorations, insurance, property research, and the cash needed after closing for the home, permits, utilities, site preparation, delivery, setup, and inspections. Ask the lender and closing professional which figures are estimates, final disclosures, paid before closing, credited at closing, or outside the real-estate transaction.