No. Substantiality is proportional: the question is whether the amount is enough to make this particular enterprise operational, measured against what such a business costs to buy or establish. A modest service business can qualify on a sum that would be plainly inadequate for a factory.
Proportion, not a threshold
Hypothetical example: Guenther runs a custom cabinetry shop in East Ferris and is buying a small American millwork business at a price a broker told him is too low for E-2. There is no such thing as too low in the abstract. The question is what this business needs in order to operate: if the purchase price together with the machinery, the leasehold improvements, the opening inventory and the working capital fund a functioning company, the proportion is right.
Where a business can be bought cheaply, a smaller absolute figure is expected to represent a higher proportion of the total. The related trap is marginality. A shop generating only a living for Guenther and his family does not qualify, so the plan has to show present capacity to do more, or a credible path to it within about five years, supported by contracts, backlog and a staffing schedule rather than an assertion about market growth.