Relative to the enterprise, not against a fixed figure. The benchmark is the total cost of establishing or purchasing a business of that type and getting it operating.
Price the whole start, not the down payment
Proportionality is the point. For an existing business bought as a going concern, the reference is the purchase price; for a start-up, it is what it genuinely costs to open and run that kind of operation. Plans understate this in predictable ways: leasehold improvements, licences and permits, insurance, deposits, initial inventory, the first months of payroll before revenue arrives, and professional fees for incorporation and closing. A plan that funds the purchase and nothing else invites the conclusion that the enterprise is undercapitalised, which bears on both the substantiality and the marginality questions. Nonimmigrant visa fees and any reciprocity charges are published in official Department of State materials and should be included in the budget.
There is no universal E-2 dollar figure. The investment is assessed in relation to the cost of the specific enterprise and must be substantial enough for that context. Separate business purchase expenses from government, legal, and personal relocation costs; only the documented enterprise commitment answers the investment question. Hypothetical example: a specialty-bakery buyer includes future household rent in the investment total; the closing statement and business invoices distinguish committed business funds from personal spending.
Review recurring operating reserves separately from acquisition costs, since a sound business budget does not make personal relocation spending part of the qualifying commitment.