How do you know this method isn't more efficient without looking at prices? It might be especially relevant in countries where a large part of the cost of build

How do you know this method isn't more efficient without looking at prices? It might be especially relevant in countries where a large part of the cost of building a new house is labor costs. For my part, I can't tell if this new method is more efficient without this team selling or leasing their printer, so we can know how much it costs to build a house with their machine vs laying bricks manually (for various countries).