Yes. In Australia at the moment, there are about a million of these tests used per year. Yes, there are some economies of scale, but there's a limitation on the quality of the antibodies used in the kit. Good-quality antibodies provide for a good-quality test. One would judge the use of $50 against the cost of one, two or three hours of police manpower. In fact, these kits are very economical if the policeman can use a kit and get the evidence—yes or no—immediately.
On September 27th, 2017. See this statement in context.